Dell Ultrasharp U3011......Professional review

Above: Dell U3011

Over the last year or so we have seen a full refresh of Dell's premium monitor lineup, along with some updates in the more commercial and cheaper range. In their popular UltraSharp series we have had: the update of the 24" 2408WFP to the U2410, introducing IPS panel technology into their 24" sector for the first time. An update to their 2709WFP model, bringing out the new 27" U2711, again with IPS for the first time. Both these models have also introduced panels with 10-bit colour depth capabilities, again a first for the Dell range. There was also the release of new 21.5" and 23" models, with the U2211H and U2311H respectively. These again stuck with the IPS panel technology theme and plugged a previously empty niche in their collection. We have taken an in depth look at all four of these models as and when they've been released. Today, we have the latest update in the range, the new U3011. This is an update to the popular 3008WFP screen, but in this case the previous screen also used IPS panel technology as well as the new model. Dell have still used an updated 10-bit capable panel as they did with the 24" and 27" models, and there are some other changes with the new model. We also have the 3008WFP here for direct comparisons, so we hope to be able to tell you exactly what has changed, what has improved, and what has not.

Let's take a look at the specs for the U3011 first:

Size	30"WS	Colour Depth	1.07 billion colour panel (10-bit)
Aspect Ratio	16:10	Colour Gamut	102% NTSC colour gamut
Resolution	2560 x 1600	Viewing Angles	178/178
Response Time	7ms G2G	Panel Technology	H-IPS
Contrast Ratio	1000:1 and 100,000:1 DCR	Interfaces	DVI x2 (with HDCP), D-sub, 2x HDMI, DisplayPort, component
Brightness	370	Colour	Black bezel and base with silver stand
Special Features	Tilt, pivot and height adjustment. USB 2.0 ports x4, 7-in-1 card reader, factory calibrated sRGB and Adobe RGB modes
Buy	PCBuyIT.co.uk

Above: Front, side and rear views of the U2711. Click for larger versions

The U3011 is the same design at the smaller U2711 and U2410 models. There is a fairly thin (25mm) black bezel around the panel, and a silver and black stand. The screen size is massive, dwarfing my regular 24" monitors which we use day to day and feeling noticeably bigger than 27" models as well. The screen is a 16:10 format. Materials were of good quality and the screen felt well built and pretty sturdy overall. The design of these new models feels a little 'blocky' in my opinion, with no real rounded edges. At this kind of size, its even more noticeable than the U2410, especially with the bigger stand footprint and the thicker bezel trim.

The panel itself features a matte Anti Glare (AG) coating as opposed to any glossy solution. The panel actually sits a little bit back from the front of the bezel by about 5mm which is a little deeper than on most screens. The coating was very similar to that on the U2410 and U2711 but I personally didn't find any serious problems with it being too grainy or anything, and it was also very similar to the S-PVA based Dell 2405FPW. The graininess is more apparent on white and lighter backgrounds. I know some users don't like the feel of the coating or prefer glossy solutions, so if you're worried try and see one of Dell's current range in action in person. I know there's been a lot of complaints about the graininess already but it's all down to personal taste so I won't labour the point.

There is a decent range of ergonomic adjustments available from the new screen. There is a pretty decent 100mm height adjustment range, although the maximum height of the screen is not that high really. At the lowest height setting, the bottom of the screen is approx 35mm above the desk which is very low. At maximum height extension the bottom of the screen is about 135mm above the desk. It does afford a good range of heights to be selected, but doesnt not extend as high as some other stands we have seen. This adjustment is smooth and easy to manoeuvre which is good. There is also a good tilt function, again pretty easy to adjust. The pivot movement is a little stiffer but despite the size and weight of the screen is perfectly useable and does not involve you moving the whole base when you make adjustments which was good. There is no rotate function from the U3011 which is due to the size of the screen, and not really missed in my opinion.

Above: Height adjustment shown

The left hand side of the screen features a 2 port USB hub for easy access. There are also 2 further ports next to the interface connections on the back underside of the screen (shown below). The 7-in-1 (not 9-in-1 like the U2410 or even 8-in-1 like the U2711) card reader is also featured on the side for easy access and is very handy for cameras and memory cards.

The underside of the screen at the back features all the connections you might need. Nice to see 2x DVI here for connection of multiple PC's via a digital signal, both of which are HDCP certified. Also good to see two HDMI ports and a DisplayPort here as well for connection of external multimedia devices and to keep up with connection trends in the market. There's also component available for connecting some other devices, common in games consoles, DVD players and video cameras for instance. It seemed to take a fairly long time to switch to a digital input and power up initially when using DVI. This took about 7 second to do. Switching from DVI to VGA took about 2 seconds, but switching back took 7. This is related to the interface chip and I'm only mentioning it as I'm aware some people have talked about it across the web with the U2711 model, and the same is evident here on the U3011. A minor point.

The OSD operation buttons are very subtle and located on the bottom right hand edge of the screen. The power LED glows a blue colour when in operation and pulsates a subtle orange colour in standby. The other selection buttons are hidden until you hover your finger over the bottom button, at which point they all light up and pressing them gives access to the OSD menu. The OSD menu buttons are not labelled in any way. Instead, when the menu pops up, there are indicators on the screen itself telling you what each button does. I actually really liked this style of menu and it was easy to use and navigate, and very intuitive. By default the pressing of these buttons has an associated 'beep' sound which thankfully can be turned off in the menu as well as I find it quite annoying.

When you first press the bottom sensor button you are presented with the quick launch menu options. You have quick access to preset modes, brightness / contrast controls, input source and an option to enter the full menu.

Entering the preset quick launch reveals the above sub-menu. You may notice that there's actually an extra preset available on the U3011 which was not present on the U2410 or U2711. This is the 'movie' mode which we will talk about a little later on.

 

Entering the main menu gives you an even wider range of options. The input source section for instance is shown above, allowing you to flick between the various inputs available from this screen.

The OSD section for display settings is also shown, where you have access to the hardware aspect ratio controls (fill, aspect, 16:9, 4:3 and 1:1) and access to the dynamic contrast ratio if you want to use it and if you are in suitable preset modes where it is available.

While there are no integrated speakers with the U3011 model, the screen is compatible with Dell's soundbar if you want, at an additional cost.

In terms of power consumption the spec states typical usage of 110W (assuming no audio or USB connections) and less than 2W when in standby / sleep mode.

State Power Usage (W) Factory Default 104.8 Calibrated Settings 85.7 Standby 2.0

We tested this ourselves and found that out of the box the screen used 104.8W of power. This was reduced to 85.7W after calibrated (see calibration section) since we had reduced the OSD brightness control considerably. In standby, the screen used only 2.0W of power. The screen did become reasonably warm at the top on the back of the display, but nothing too bad. There was no noise or buzzing detectable from the screen even up close.

Colour Accuracy, Black Depth and Contrast

The Dell U3011 utilises a 10-bit H-IPS panel, capable on paper of producing 1.07 billion colours. The panel itself (reported to be LG.Display's LM300WQ5-SDA1) is listed as a 10-bit panel, but true 10-bit support does require an end to end "10-bit journey". Although we have not 100% verified this, the panel is most likely technically an 8-bit with A-FRC technology, supporting up to 10-bit colour. This would fit in with the U2410 and U2711 models as well. Have a read of this article which discusses it in more detail. It should be noted that the LM300WQ5 was also used in the 3008WFP display as well. This was the LM300WQ5-STA1 revision, which only supported 8-bit colour and a 16.7m colour palette. The panel has been updated for 10-bit colour support and 1.07b colours, and caries with it a new revision number.

It's all very well saying a panel is capable of 10-bit colour depth (1.07 billion colour palette) as opposed to an 8-bit colour depth (16.7 million colours), but you need to take into account whether this is practically useable and whether you're ever going to truly use that colour depth. Apart from the requirements of your application, operating system, graphics card and software, one more pertinent limitation is from a display point of view, where there must be an interface which can support 10-bit colour depth. At the moment DisplayPort is the only option which can. It is provided here, but a full 10-bit work flow is still extremely uncommon in the current market.

Regardless of whether you have a true 10-bit colour depth being displayed, a screen with 10-bit capabilities still has its advantages. The monitor should still be capable of scaling the colours well, even from 24-bit sources. Most of these 10-bit panels will also be coupled with extended internal processing which will help improve accuracy and these are better translated onto a 10-bit panel than they would be onto an 8-bit panel, giving less deviation and less chance of banding issues. Although the U2711 offered a 12-bit internal colour processing to help offer smooth gradients and provide clarity in subtle detail, no such spec is listed against the U3011.

Like many modern displays, the screen uses enhanced W-CCFL backlighting and can offer a colour gamut covering 102% of the NTSC colour space. This also covers 100% of the sRGB colour space and 96% of the Adobe RGB.

An important thing to consider for most users is how a screen will perform out of the box and with some basic manual adjustments. Since most users won't have access to hardware colorimeter tools, it is important to understand how the screen is going to perform in terms of colour accuracy for the average user. I restored my graphics card to default settings and set it to its standard profile. The U3011 was tested at default factory settings using the DVI interface, and analysed using LaCie's Blue Eye Pro colorimeter and their accompanying software suite.

Default settings of the screen were as follows:

Monitor OSD Option	Default Settings
Brightness	50
Contrast	50
Preset mode	Standard

Dell U3011 - Default Factory Settings

	Default Settings
luminance (cd/m2)	179
Black Point (cd/m2)	0.23
Contrast Ratio	780:1

The results of the U3011 at factory settings were very good really. On the left you can see the CIE digram demonstrating the colour space of the monitor (black triangle) against the reference sRGB space (orange). The screen has an extended colour gamut thanks to the use of W-CCFL backlighting, and the colour space stretches considerably beyond the sRGB standard in green and red shades. Wide colour gamuts are not for everyone though, and I would thoroughly recommend a read of this article over at X-bit Labs, which covers the pros and cons well. In terms of the performance of this screen, this result is what we were expecting given the monitor is specified with a 102% gamut. No issues here, just confirmation of the extended colour space.

Gamma was actually pretty well set up out of the box with a reading of 2.1 average, being only 2% out from our target of 2.2 which is the default for computer monitors. We know also that the sRGB and AdobeRGB preset modes have been factory calibrated to provide accurate gamma and colour accuracy. We will look at that in a moment, but it was pleasing to see a good gamma set up even in the standard preset and when the full colour space is being used. Colour temperature was recorded at 5804k, a little way out (11%) from our target of 6500k, the colour of daylight. Luminance was a bit too high at default as well (this was at 50% brightness setting), being 179 cd/m², a bit off our target of 120 cd/m² which is the recommended luminance for LCD screens in normal lighting conditions. Having an overly bright factory setting is pretty common from modern screens, but if nothing else you will want to tone the OSD brightness down to find a more comfortable setting. We will have a look at this a bit more in our contrast stability section shortly, but you may need to turn the brightness control down to 0 - 10% even. I found the setting of 50% to be uncomfortable for any prolonged use. Black depth was recorded at a pretty decent 0.23 cd/m², giving a static contrast ratio of 780:1. Another pretty decent result from an IPS panel here in this regard.

In terms of colours you could tell the screen had an extended gamut to the naked eye. The greens and reds looked vivid and bright compared with an sRGB display. For my uses, I have no issue really using an extended gamut screen for every day browsing and writing, but if you are doing anything colour critical or working with certain colour spaces (e.g. sRGB), you need to read more about gamuts as I've mentioned above.

Testing with the colorimeter revealed the graph on the right hand side above, showing DeltaE (dE 94) values across 16 shades. As a reminder, the lower these bars down the Y-axis, the better, in terms of colour accuracy. For reference, LaCie describe the DeltaE readings as:

• If DeltaE >3, the color displayed is significantly different from the theoretical one, meaning that the difference will be perceptible to the viewer.
• If DeltaE <2, LaCie considers the calibration a success; there remains a slight difference, but it is barely undetectable.
• If DeltaE < 1, the color fidelity is excellent.

The default settings offered a very good colour accuracy. dE average was 1.7 leaving a slight difference between the colours being requested and those being displayed. This ranged up to 4.6 in the worst cases in the green shades. Not a bad performance at all. You also have factory calibrated profiles available in Adobe RGB and sRGB mode which should help offer good colour accuracy in reduced colour spaces (more below).

Factory Calibration

The Dell U3011 comes factory calibrated to some extent, and the box even includes a calibration report from Dell specific to the unit you have. It states that every unit is shipped incorporating pre-tuned sRGB and AdobeRGB settings and with an average DeltaE of <5. In LaCie's classification, this is still not great, but the thought is at least there and some attempt has been made to factory calibrate the screen. In addition to this, they have tweaked gamma and other settings to provide tighter grey scale tracking which helps to ensure smooth gradients. I've included a copy of the calibration report from the Dell factory below for you to review. Note that this report is only relevant to my specific test unit and they do state that results may vary with each setup and different test equipment.

I was interested to see if this factory calibration helped at all with default settings. Note that this is only relevant for the sRGB and AdobeRGB (aRGB) preset modes available through the OSD menu. You will need to change from the default 'Standard' profile to benefit from these factory calibrated settings.

Dell U3011 - Factory Settings, Adobe RGB Mode

	Default Adobe RGB Mode
luminance (cd/m2)	168
Black Point (cd/m2)	0.23
Contrast Ratio	730:1

The AdobeRGB gamut triangle is shown on the let as a reference, with the monitors colour space fitting this pretty closely. It did exceed the AdobeRGB space slightly in red tones although the colour space was being reduced slightly in this area compared with the standard preset and full native colour space. The mode is designed to fit the AdobeRGB as closely as possible, and so it does a fairly good job here.

Gamma was still pretty much spot on using this factory calibrated profile (3% deviance), but colour temperature and luminance were a fair way out from the targets at 5452k (16% out) and 168 cd/m² (40% out) respectively. Colour accuracy was not quite as good as the standard prest sadly, but was within the factory calibration criteria of dE <5. This preset gave us dE average of 3.3 and a  maximum dE of 7.4. This was not as well calibrated in the factory for Adobe RGB as we had seen from the Dell U2711 (1.7 average dE) or U2410 (2.9) which was a shame. Perhaps they have spent less time and money factory calibrating the larger screen in the assumption that more users are likely to have access to a hardware colorimeter?

Dell U3011 - Factory Settings, sRGB Mode

	Default sRGB Mode
luminance (cd/m2)	168
Black Point (cd/m2)	0.23
Contrast Ratio	730:1

Dell have included an sRGB emulation mode in the new U3011 in keeping with that offered on the U2711 and U2410. Some extended gamut displays incorporate this hardware emulation as a way to limit the colour space being used if you need or prefer to work with sRGB content. These emulation modes work to varying degrees, and we've seen some which offer absolutely no reduction in the colour space (e.g. HP LP2475W) or other models where the colour space is reduced, but getting accurate colours was impossible (e.g. Dell 2408WFP).

Again, the colour space fits fairly closely with the sRGB reference, only being a little way out in red shades and green shades. It couldn't actually cover the sRGB space as well as the emulation mode from the U2410 or U2711 which was a shame, leaving more of a gap in greens and stretching even further in red shades. Reds may appear over-saturated or too 'neon' even in this emulation mode, but it's certainly cut the green colour space back compared with the extended gamut modes.

Gamma was again very good (4% out), but you would still need to calibrate to reach the desired colour temperature and luminance. This emulation mode returned similar coloour accuracy to the Adobe RGB mode. dE average was a moderate 3.5, with maximum still quite high at 7.3. The performance of the sRGB mode was very comparable to the AdobeRGB mode. We will see shortly whether these modes can be calibrated successfully.

 

Calibration Results

I wanted to calibrate the screen in each of the main preset modes to determine what was possible with optimum settings and profiling. I use the LaCie Blue Eye Pro colorimeter and software package to achieve these results and reports.

Dell U3011 - Calibrated Settings - Custom Color Mode

Monitor OSD Option	Adjusted Setting
Brightness	5
Contrast	50
RGB	89, 98, 91
Preset Mode	Custom Color

	Calibrated Settings, Custom Color Mode
luminance (cd/m2)	119
Black Point (cd/m2)	0.17
Contrast Ratio	700:1

To carry out this initial calibration I switched to the custom color preset mode which affords me access to the full range of RGB controls in the OSD. I followed LaCie's calibration process through, adjusting the OSD settings in line with the recommendations made in the process, and then letting the software carry out the LUT adjustments at a graphics card level and create an ICC profile. The screen does not feature a hardware LUT calibration option so other than the OSD alterations, the rest of the process is carried out at a graphcis card level in profiling the screen.

The calibration was a success. While gamma was already very accurate out of the box as we had seen, it had obviously done a good job at adjusting colour temperature and luminance as you can see above, both being pretty much spot on now compared with our target settings. Black depth was a little lower now as well at 0.17 cd/m², but contrast ratio was reduced a little as well to 700:1. This was an improvement over the black depth of the U2410 which was calibrated to 0.22 cd/m² and also better than the U2711 (0.18).

Colour accuracy was also corrected nicely as well, offering a much better result than the factory default. Average dE was now 0.5 with a maximum of only 1.8. LaCie would consider colour fidelity to be excellent now on average, although there were some slight differences in some cases. This is a good result when you consider the U2410 had some big problems adjusting and correcting colour accuracy in the 'custom color' preset, only allowing us to get dE average of 3.2 at best and max of 10.8. We had to revert to the standard preset to get the best performance out of the screen with the 24" model. Thankfully the custom color profile on the U3011 works fine.

Testing the screen with colour gradients revealed some gradation in darker tones, but no banding or issues were present. The gradients were perhaps not quite as smooth as the NEC PA271W we had tested recently, but the U3011 is lacking the internal processing and hardware LUT correction that the PA series offer. You can use our settings and calibrated ICC profile on your U3011 as well if you want. See our ICC profile database for more information.

Dell U3011 - Calibrated Settings - Standard Preset Mode

	Calibrated Settings, Standard Mode
luminance (cd/m2)	121
Black Point (cd/m2)	0.16
Contrast Ratio	727:1

One of the odd 'features' of the U2410 was that it did not seem possible to calibrate the custom color preset properly, and so we had to revert to the standard mode to get the best results. This was not a problem on the U2711 thankfully, but I wanted to check whether calibration of the standard profile on the U3011 produced any different results to our already very good calibration above. All OSD settings were left as they were, but changing back to the standard preset meant RGB controls were not available at all. All corrections would be carried out by the automatic calibration process and at a graphics card LUT level.

Gamma remained accurate as it was well calibrated out of the box at default settings. Colour temperature and luminance were corrected nicely as they had been 10% and 49% out from the targets respecitively before. Black depth was slightly better as well at 0.16 cd/m², giving us a static contrast ratio of 727:1. Colour accuracy was also very good with average dE of 0.3 and max of 0.7. A massive improvement from the default settings where average was 4.3 and maximum was 11.1. This was actually a little ahead of the custom color calibration where average was 0.5 and max was 1.8. You can get good results from both presets, but the standard perhaps has the slight edge on this model. Again, ICC profile available if you want it in our ICC profile database.

Dell U3011 - Calibrated Settings - Adobe RGB Preset Mode
 

	Calibrated Settings, Adobe RGB Mode
luminance (cd/m2)	120
Black Point (cd/m2)	0.18
Contrast Ratio	666:1

I reverted to the Adobe RGB preset mode again to determine whether this mode allowed for decent correction of colours. Factory calibration had been a little disappointing in terms of colour accuracy, with an average dE of only 4.3. In this preset, the brightness control was increased slightly to 12 (from 5 in our custom color and standard preset calibrations). It should be noted that the OSD brightness setting does not save individually for each preset mode, so you would have to change it again manually if you wanted to revert to the other modes where we had set this at 5%. Again, there was no access to the RGB controls in this preset so corrections would be carried out at a graphics card LUT level via the profiling.

Gamma remained very accurate, correcting the slight 2% deviation we saw at factory settings in this preset. Colour temperature was corrected very well to 6505k from the default of 5351k (18% deviation). Luminance was now 120 cd/m², and with a black depth of 0.18 cd/m² we had a contrast ratio of 666:1. This was not quite as good as in the standard (727:1) or custom color (700:1) modes. dE average was now 0.5, and max of 1.2. Nice to see that calibration can correct the colours in this preset mode as well since they had been pretty poor out of the box at 4.3 / 10.9. Again, ICC profile available if you want it in our ICC profile database.

Dell U3011 - Calibrated Settings - sRGB Preset Mode

	Calibrated Settings, sRGB Mode
luminance (cd/m2)	120
Black Point (cd/m2)	0.18
Contrast Ratio	665:1

I tested the screen as well in the sRGB preset which returned moderate results in default mode with the factory calibration. Gamma was set up correctly by this factory calibration but colour temp and luminance were significantly out from the target points (17% and 40% respectively). Colour accuracy was fairly good, with dE average of 2.6 and 9.3 maximum. Some screens don't let you calibrate very well in sRGB emulation mode, but we had some good results with our test of the Dell U2410 and U2711 before. Thankfully the U3011 performed well here, allowing us to improve the colour accuracy to 0.4 average dE and 1.3 maximum. The other targets were also met nicely. Overall a very good result.

Colours of course looked less vivid in this sRGB emulation mode but that is to be expected when working with a smaller colour space. Again, ICC profile available if you want it in our ICC profile database.

One thing which users found on the original A00 release of the U2410 was that when operating in sRGB and Adobe RGB preset modes, colour gradients showed an odd 'dithering' type issue in darker tones. It seemed some colours were being dropped, and in darker shades gradients were no longer smooth. Instead there was an obvious sign of spatial dithering and noticeable patterns in the darker shades. In January, Dell accidentally leaked a firmware upgrade for the U2410 which disabled the FRC in these two preset modes, and resolved the issue with the dithering artefacts. I checked the U3011 in sRGB and AdobeRGB modes in case it suffered from the same problem, but I'm pleased to report it did not. No issues here in any of the preset modes which was also the case with the U2711 before it.

 

Calibration Performance Comparisons

I have plotted the results of these tests above compared with some of the popular and competing models we have tested. As you can see the U3011 offers some of the best default colour accuracy available, with an average dE of only 1.7. This was a little behind the NEC PA271W (1.1) but that is of course a professional grade colour enthusiast screen. Of course the NEC PA series also offers other high end features which separate them from some of these other models, including extended internal processing, 3D LUT's and hardware calibration. These comparisons are based on a small selection of tests, so it should be remembered that other factors do come into play when you start talking about professional use.

The U3011 was certainly superior to the U2711 (3.7 dE average) and U2410 (6.7) out of the box when it comes to colour accuracy. It was also a fair bit ahead of the Hazro HZ30Wi (4.5) which we tested recently. Once calibrated the screens were all quite similar, although the TN Film based 27" VX2739wm was a little behind (0.7). Good calibration results from the U3011 and in keeping with the U2711 before it.

The U3011 offered a slightly better black depth (0.16) than the U2711 (0.18) and U2410 (0.22) which was a good result. A couple of the other models such as the NEC EA231WMi and Dell U2311H were slightly ahead though (0.15 and 0.14 respectively). Contrast ratio was good from the U3011 at 727:1, again ahead of the U2711 (672:1) and a considerable improvement compared with the U2410 (541:1). It was a little behind a couple of the other models, but did just beat the other 30" models shown here, the Dell 3008WFP (673:1) and Hazro HZ30Wi (713:1).

 

Contrast Stability

I wanted to see how much variance there was in the screens contrast as we adjusted the monitor setting for brightness. In theory, brightness and contrast are two independent parameters, and good contrast is a requirement regardless of the brightness adjustment. Unfortunately, such is not the case in practice. We recorded the screens luminance and black depth at various OSD brightness settings, and calculated the contrast ratio from there. All other monitor and graphics card settings were left at default with no ICC profile or calibration active. It should be noted that we used the BasICColor calibration software here to record these, and so luminance at default settings varies a little from the LaCie Blue Eye Pro report.

OSD Brightness	Luminance (cd/m2)	Black Point (cd/m2)	Contrast Ratio ( x:1)
100	302	0.38	796
90	284	0.36	789
80	235	0.31	757
70	208	0.27	772
60	190	0.25	761
50	174	0.23	758
40	165	0.21	784
30	156	0.20	780
20	146	0.19	771
10	138	0.18	764
0	128	0.17	755

The luminance of the panel ranged from 302 cd/m² at maximum brightness (100%) down to 128 cd/m² at the lowest setting. The maximum luminance was a little short of the specified 370 cd/m², but in reality I doubt many people need to use the screen at this kind of setting anyway. The screen was very bright and too uncomfortable for any prolonged use. At the lower end it was a little disappointing to see that the minimum setting only allowed you a luminance of 128 cd/m². This is pretty high and many users will want to be able to go below this in practice. The U2711 allowed you to reduce luminance to 49 cd/m² at the 0% setting for instance. Perhaps the 100% setting should have been set at a lower backlight intensity to allow you to control the luminance lower than this at the bottom end.

Black depth ranged from 0.38 cd/m² at the maximum brightness setting, down to 0.17 cd/m². Contrast was pretty stable across the range, at around 772:1 average. The results were also plotted on the graph below:

Dynamic Contrast

The Dell U3011 features a dynamic contrast ratio (DCR) control, which boasts a spec of 100,000:1. This is obviously a pretty huge number and requires the screen to be able to produce a very bright white, and a very dark black at the two ends of the control. Dynamic contrast ratio involves controlling the backlight of the screen automatically, depending on the content shown on the screen. In bright images, the backlight is increased, and in darker images, it is descreased. For this test I would use the colorimeter to record the luminance and black depths at the two extremes. Max brightness would be recorded on an all white screen once the DCR has caught up. Black depth would be recorded on an all black screen.

The DCR feature can only be selected through the OSD when you have entered the 'game' or 'movie' preset modes. Not sure why it wouldn't be available in 'multimedia' mode to be honest as well, but at least with the U3011's added 'movie' preset (compared with the U2410 and U2711) there is another preset for watching films, and in which the DCR can be activated. While this mode is in use, you cannot manually adjust the brightness or contrast settings in the OSD without it turning this feature off. The changes are very smooth and sublte so are not going to be too obvious to the naked eye as content on the screen changes.

	Calibrated Settings, Game Preset Mode
Max luminance (cd/m2)	182
Min Black Point (cd/m2)	0.20
Max Dynamic Contrast Ratio	910:1

The dynamic contrast ratio control didn't seem to do much to be honest. We'd run the same test with the U2410 and only achieved a dynamic contrast ratio of 1402:1, and with the  U2711 we had only reached 759:1. The DCR mechanism didn't seem to want to reduce the brightness down far enough when dark content was being displayed, and so black depth was rather mediocre at 0.20 cd/m². At the top end, the luminance only reached 182 cd/m², and we've already seen in our contrast stability tests that 100% brightness only yeilds a luminance of 302 cd/m² tops. At 0% brightness black depth also only reaches 0.17 cd/m². If the DCR mechanism was capable of controlling the full brightness range of the backlight, you'd see a maximum DCR of 1776:1.

Even if the screen could reach the maximum specified brightness of 370 cd/m², you'd need a black depth of 0.0037 cd/m² to give you an overall dynamic contrast ratio of 100,000:1 so this spec is surely exagerated. I'm not sure why Dell and other manufacturers insist on pushing ridiculously high DCR specs when they aren't achieveable in practice.

Viewing Angles

Above: Viewing angles shown from front and side, and  from above and below. Click for larger images

Viewing angles of the U3011 were very  good. There was minimal contrast shift horizontally and the IPS panel technology exibited wide fields of view in this regard. It was free from the off-centre contrast shift which you see from VA matrices. Vertically there was a slightly more pronounced contrast shift as you moved away from a central point, but the panel was certainly free from the very restrictive viewing angles you see from TN Film based screens. No complaints here in relation to viewing angles. On a black image there was a characteristic H-IPS white glow from an angle as the panel does not use an A-TW polarizer.

Panel Uniformity

Measurements of the screens luminance were taken at 35 points across the panel on a pure white background. The measurements were taken using BasICColor's calibration software package, combined with the LaCie Blue Eye Pro colorimeter. The above uniformity diagram shows the difference, as a percentage, between the luminance recorded at each point on the screen, as compared with the reference point of a calibrated 120 cd/m². This is the desired level of luminance for an LCD screen in normal lighting conditions, and  the below shows the variance in the luminance across the screen compared with this point. It is worth noting that panel uniformity can vary from one screen to another, and can depend on manufacturing lines, screen transport and other local factors. This is only a guide of the uniformity of the sample screen we have for review.

Uniformity of Luminance

The uniformity of the panel was reasonable. The luminance did vary from left to right though. Along the left hand edge the luminance dropped by about 20%, with a worst case of 89 cd/m² being measured in the bottom left hand corner (35% deviance). On the right hand half of the screen we recorded a slightly elevated luminance, ranging up to 126 cd/m² maximum (the centre had been calibrated at 120 cd/m²). 71% of the screen remained within 10% deviance from the target luminance which was good, but the discrepencies along the left hand side were a little disappointing.

I tested the screen with various coloured backgrounds including greys and whites to see if there was any sign of colour tinting across the panel. On a light grey background you could just about pick out the luminance difference, with a slightly darker left half of the screen being detectable with close inspection. There was no obvious colour casting across any part of the screen thankfully from our sample.

Above: All black screen in a darkened room. Click for larger version

As usual we also tested the screen with an all black image and in a darkened room. A camera was used to capture the result. The uniformity of the backlighting was very good in this test. There was some very slight leakage in the corners as you can just about pick out in the image, but it was very minor. There was no severe leakage from any corner or edge which was good to see.

General and Office Applications

We've reviewed quite a few ultra-high resolution screens recently, from the 27" 2560 x 1440 models (Dell U2711, NEC PA271W) to the 30" 2560 x 1600 Hazro HZ30Wi. It takes quite a bit of adjustment when you move to a 30" screen as the sheer size of it is quite overwhelming. We tend to use 24" monitors day to day and now they just look tiny next to this monster! The extra screen size and massive 2560 x 1600 resolution really gives you a lot more room to work with though, and you can easily carry out split screen working with multiple applications and windows open. It would be an excellent choice for any multi-tasking applications where you need to split the screen into sections. It's a little bit bigger vertically than the modern 27" screens which have a 16:9 aspect ratio and 2560 x 1440 resolution.

The screen has a 0.2505mm pixel pitch as standard for a 30" model. This is a bit smaller than a standard 24" model which is 0.270mm. Text does appear smaller as a result, and personally I find it a little too small for long term office use. It's not as small as some of the new generation of 27" screens with ultra-high 2560 x 1440 resolutions (0.230mm) which is good. Worth trying to see one in action if you are worried at all about font size.

The image was very sharp and crisp and text was very clear using the Dual Link DVI interface. The analogue D-sub interface cannot support the full native resolution of the panel so a comparison of picture quality is not easily made. The decent range of ergonomic adjustments made it easy to get a comfortable position for the screen as you would hope although the maximum height adjustment was not that great. The wide range of preset modes should allow you to set the screen at an optimum setting for your use. It would have been useful if the OSD adjustments for brightness were saved individually for each preset mode though.

The added 4x USB ports are useful for connecting external devices and it was good to see two on the left hand edge for quick access. The card reader is also useful I think and a nice feature which Dell have included for several years now. There's no auto brightness control which I personally think can be useful in changing ambient lighting conditions.

Responsiveness and Gaming

The Dell U3011 was tested using the chase test in PixPerAn, a good bit of software for trying to quantify differences in real terms responsiveness between monitors. As a reminder, a series of pictures are taken on the highest shutter speed and compared. The images below show the best case example on the left hand side, and the worst case example on the right hand side. This should only be used as a rough guide to comparative responsiveness but is handy as a way of keeping a constant test of each screen.

30" 7ms G2G LG.Display H-IPS


30" 8ms G2G LG.Display H-IPS

30" 8ms G2G LG.Display H-IPS

27" 6ms G2G LG.Display H-IPS

24" 6ms G2G LG.Display H-IPS

The U3011 uses LG.Display's latest 30" LM300WQ5 H-IPS panel. This utilises response time compensation (RTC) to boost the response time across grey to grey transitions and the manufacturer quotes the minimum response time for the panel to be 5ms G2G. Dell have re-classified the panel at 7ms G2G according to their specs however, which is a 1ms improvement compared with the 3008WFP model which preceeded it and also used this panel. Obviously these are just specs on paper, and real life responsiveness can vary. We have provided the PixPerAn images above alongside 4 other very popular models in the market, all using H-IPS panel technology.

The responsiveness of the U3011 was actually very pleasing. There was no obvious ghosting of moving images and motion blur was actually fairly minimal. Furthermore, there was no evidence of RTC overshoot in the form of white or dark halos which was very pleasing. Sometimes when RTC is used to boost response times it can lead to an unfortunate trail behind a moving image where the RTC impulse is too aggressive or poorly controlled. You will spot this for instance on the Dell U2711 where the PixPerAn images show a dark trail behind the moving car and speach bubble. Thankfully the RTC impulse seems to be well controlled on the U3011.

The screen did feel ever so slightly faster than the 3008WFP which we also have with us for testing at the moment. I ran the screens side by side and although they were very close, the U3011 did seem to have a slightly sharper image in moving scenes and a less pronounced blur. This was picked up in this test as well and you will see the trial image is a little less obvious on the U3011. The Hazro HZ30Wi (using a slightly different LM300WQ3 panel) was again very comparable to both, being somewhere in between in terms of responsiveness in practice.

3ms G2G Samsung TN Film + 120Hz

For comparison I have also put the results from our current reference screen above, the Samsung SM2233RZ. This shows the type of responsiveness that is possible from a modern display. The Dell still performs very well as you can see, but there is still a slight blurred trail even in the best case image, something which is almost none-existant in the Samsung test. The Samsung is also free of the RTC overshoot artefacts, and this is largely due to the use of 120Hz technology which helped eliminate these issues in our tests.

As a side note, the screen does feature a game preset mode which affords you access to the dynamic contrast ratio control if you want to use it. Some gamers like this as a feature, some do not so that's down to preference. We've already had a look at the feature, and while it works to some degree it does not seem to reach anywhere near the specified DCR.

There is also hardware aspect ratio control available through the OSD with options for fill, 16:9, 4:3, aspect and 1:1 pixel mapping. This is actually a wider choice than was available from the U2711, U2410 and 3008WFP which was a pleasing upgrade.

 

Input Lag

As usual I tested the screen in clone mode with a CRT to determine the level of input lag. This is something which can put off some gamers and is a delay between graphics card and monitor output. By hooking up a CRT you can show that  the LCD lags behind somewhat, which can affect users in some situations where they rely on the screen image being as fast as their inputs (e.g. fast FPS shooting games). Often, input lag is very low and probably wouldn't represent too much of a problem in real terms.

The average input lag of the U3011 was a fairly moderate 24.4ms. Maximum ranged up to 30ms in some circumstances. This was a reasonable performance really all in all, being pretty comparabale to the U2711 (30ms). It was also pretty similar, in fact a little faster, than the U2410 which clocked in at 33.8ms when in normal mode. However, the 24" U2410 also provided a game mode which bypassed a lot of internal electronics and did help reduce the input lag significantly down to 14.4ms. This was an added feature of the U2410 specifically aimed at gamers and those sensitive to input lag. You'll also see this on some other models such as the NEC 24WMGX3 where they feature a 'through mode' to do the same thing. The U2711's game mode didn't impact the input lag to any significant degree, and it was the same story from the U3011. The game mode does give you access to the DCR feature, but does not seem to act as any 'through' or bypass mode.

Movies and Video

The following summarises the Dell U3011's performance in video applications:

• 30" screen size makes it a reasonable option for an all-in-one multimedia screen, noticeably bigger than a 24" model
• 16:10 aspect ratio not quite as suited to movie viewing as a 16:9 format screen since it leaves you with larger black borders at the top and bottom for DVD's
• 2560 x 1600 resolution can support true 1080 HD resolution content (1920 x 1080)
• Digital interfaces support HDCP for any encrypted and protected content
• Wide range of interface options available for connecting external devices. 2x DVI useful for connecting two PC's and good to see 2x HDMI and DisplayPort present. Component also useful for some games consoles in particular
• Good range of ergonomic adjustments available to obtain optimum viewing position
• Viewing angles were very wide thanks to IPS panel technology. No problem viewing the screen from a variety of positions or with other people
• Compatibility with Dell's soundbar in case you need it for a casual speaker solution
• Good black depth and contrast ratio helping to ensure detail in darker scenes is not lost
• Movie preset mode introduced on this model which does give access to DCR function unlike the multimedia preset. The movie preset seems to make colours a little more vivid compared with our calibrated standard preset, particularly emphasising blues. The multimedia preset didn't noticeably change the appearance from our standard preset though.
• Dynamic contrast ratio available if you switch to 'game' or 'movie' presets, but although it works to a small degree, it does not seem to reach anywhere near the quoted 100,000:1 DCR
• There is a Picture By Picture (PbP) mode available via the OSD if you want to use it for displaying two devices at the same time alongside one another, but no option for Picture In Picture (PiP) which some other models like the U2410 feature
• Decent response time and input lag making it suitable for viewing fast moving images without obvious ghosting or severe blurring
• Panel uniformity was good, with no noticeable backlight leakage from any edge or corner. That can be distracting in movies, especially where black borders are present, but not a problem here

•