Gaming performance - It's been a topic of disagreement for a long time, ever since LCD screens started to be come popular so many years ago. The regular and hard-core CRT users would always poke fun at the poor response times initially of LCD screens, with very few early models being at all suitable for a bit of gaming. Early models were plagued by blurry images and ghost trails behind moving objects, and very few people who needed to game were persuaded that LCD's were the best for them. Over the years, response time improved, to the point where we were seeing 16ms, 12ms and even 8ms screens commonly in the market. The argument became less compelling, but still many gamers refused to make the transition and experienced too many issues with LCD technology.

Along came Response Time Compensation (RTC / Overdrive) which provided manufacturers were two important changes. Firstly, they could now reduce the grey to grey transitions of pixels quite significantly, which in practice, would offer improved responsiveness and reduced ghosting and blurring. Secondly, this allowed them to push the boundaries of the previously pretty slow VA and IPS matrices, helping to bring other panel technologies to the main stream audience. Response times had again improved signifcantly across the board, but blurring was still an issue, and the subject of frame rates started to become more important as well with improvements in graphics cards and computer processing power. While it was acknowledged that many screens were now faster than the early generations, it was still argued that TFT's were limited to 60 / 75 fps due to their 60Hz /75Hz operating frequencies.

These discussions had only limited practical point, since LCD's do not flicker in the same way as a CRT would. Even the maximum 75Hz refresh rate offered by these screens was not a true 75Hz, as it would not really provide any practical benefits and was even emulated in some monitors by the internal electronics. The panel matrix operated at 60Hz and the redundant frames were just dropped in the translation. This limitation was party related to the bandwidth of the DVI interface too. In the single-link version it allows for a refresh rate of no higher than 75Hz for 1680 x 1050 monitors and no higher than 60Hz for 1920 x 1200 monitors. CRT users would still argue that LCD screens could not offer the frame rates and refresh rates that a CRT could, and this would in trun affect their precision gaming.

Is this situation about to change? NVIDIA have been actively promoting their new GeForce 3D Vision stereoscopic glasses. Each of their lenses is a liquid-crystal shutter that opens 60 times a second. To support these glasses, the monitor must show twice the number of frames, alternating between pictures for the right and left eyes. For this to happen, the screen you are using must support a true 120Hz. Since this is a necessity to use these 3D glasses, they have timed the release to coincide with the launch of some exciting new LCD screens. The Samsung SM2233RZ we have for testing here is one of them! You may be familiar with 120Hz (and even higher in fact) LCD TV technology, but this is different altogether. TV broadcast format has not changed, and the TV's are not showing an 'honest' 120Hz picture. Instead, they use clever - and pretty effective - circuitry to interpolate additional frames, artificially increasing the frame rate to help improve motion smoothness and reduce blur. This works well in the TV market, but what we have here on the desktop, is something new.

Firstly, let's have a look at the 2233RZ spec:

 

Above: Front and side views of the screen. Click for larger versions

The Samsung 2233RZ comes in an all piano black, glossy finish. The bezel is modest at around 2cm with a slight curve to the top edge and a more pronounced curve to the bottom edge. There is a small clear plastic strip along the bottom edge as well, which looks pretty good. The power LED glows a subtle blue and is curved beneath the Samsung logo on the front. When the monitor is in standby, it flashes blue. Personally I find this a little annoying, and would rather it went off, or at least went amber like most other screens.

Above: OSD menu showing guide to buttons on right hand side, and MagicBright preset menu

The OSD menu operational buttons are situated on the right hand edge of the screen, nicely out of sight. You might think this would be a little awkward to operate and know which button is which, but when you press any of them, the menu on the screen also tells you which button is which as pictured above. There is quick one-touch access to brightness, contrast and MagicBright settings. Within the menu there are also options for colour tone (cool, normal, warm, custom), gamma (modes 1-3), and all the usual things like time-out and position. Nothing else of note really. Traversing the menu is easy enough and similar to other Samsung screens.

Within the MagicBright options there are settings including text, internet, game, sport, movie and dynamic contrast. A logo on the front of the bezel (top right) states the screen offers a 20,000:1 dynamic contrast ratio.

The screen offers only a limited tilt function from the stand. It would have been nicer to see height adjustment, pivot and perhaps even a rotate function here. The stand was fairly sturdy, but the screen did seem to have a poor centre of gravity and felt a little 'wobbly' on the desk. The materials used seemed of a good quality, but the screen did feel a little weak I thought.

The back of the screen featured an interesting flowery pattern as shown in the image above. Beneath this was a power connector and Dual-link DVI interface. Both cables are provided with the screen. There is no VGA interface here, and no cable tie which was a shame. The reason for the lack of a VGA interface, or indeed a single link DVI interface, is related to the bandwidth needed to run this screen at 120Hz. At a resolution of 1680 x 1050 and a refresh rate of 120Hz the video data stream amounts to over 4.7Gbps whereas the peak bandwidth of the single-link DVI is somewhat lower than 4Gbps. You need a dual-link DVI interface, and a specific dual-link DVI cable to use this screen at 120Hz.

The screen did come packaged with NVIDIA's 3D glasses, although I shall not be testing these as I'm only really interested in the monitor itself here. The screen typically uses 50W of power during operation, but less than 1W in standby mode.

 

Colour Accuracy, Black Depth and Contrast

The Samsung 2233RZ utilises a 6-bit TN Film panel with Frame Rate Control (FRC), capable of producing 16.7 million colours. Unlike many modern displays, the screen uses standard CCFL backlighting and so it's colour gamut covers 72% of the NTSC colour space a moderate figure compared with many modern W-CCFL and LED backlit screens with extended gamuts.

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 2233RZ was tested at default factory settings using the DVI-DL interface, and analysed using LaCie's Blue Eye Pro colorimeter and their accompanying software suite.

Default settings of the screen were as follows:

Samsung 2233RZ - Default Factory Settings

 

Out of the box, the screen didn't feel too bad really. It was perhaps a little over-bright, but not as severe as some other models we have tested. This is supported by the measurement of 222 cd/m² from our colorimeter, which confirmed that at maximum 100% brightness, the maximum luminance of the panel was fairly reasonable. This was a little way off the specified 300 cd/m² though quoted by Samsung as maximum brightness. Default black depth was a respectable 0.24 cd/m², which gave us a very good static contrast ratio of 925:1.

 

Colours felt pretty even and temperature seemed quite good to the naked eye. There was no oversaturation of colours or reds and greens feeling too neon, and you can tell that this is a standard gamut screen.

 

These observations were reflected in our readings from the LaCie Blue Eye Pro, with colour temperature being only 15% away from the target 6500k of daylight. It was recorded at 5506k which was not too bad. Gamma was accurate at 2.2 which is the target for a gamma and default for computer monitors and for the Windows operating system and sRGB colour space. The monitor offers a standard colour space (gamut) which covers approximately 72% of the NTSC colour space. You can see from the CIE diagram on the left that the triangle representing the monitors colour space pretty much covers the same area as the sRGB colour space. However, it does deviate in red and green shades, extending a little beyond the sRGB reference in red shades, and not quite reaching the full range of shades of  greens. Not a big issue really, but worth noting.

 

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.

 

Average dE here at default settings was 3.9 which is fairly average and not particularly great. Maximum dE did range up to 7.7 in some shades but overall the colour rendering was fairly even in terms of accuracy or lack there-of. Some calibration would clearly be needed to get better results from this screen, but out of the box, this was a fairly average TN Film panel performance.

 

Samsung 2233RZ - Calibrated Settings

Monitor OSD Option	Adjusted Setting
Brightness	55
Contrast	75
RGB	18 / 41 / 11

	Calibrated Settings
luminance (cd/m2)	120
Black Point (cd/m2)	0.16
Contrast Ratio	750:1

 

Calibration of the screen using the LaCie Blue Eye Pro colorimeter and software produced some pleasing results. Gamma, colour temperature and luminance were all corrected nicely, with <1% deviation from the targets on all measurements. Black depth was also reduced to a very good 0.16 cd/m², giving us a contrast ratio of 750:1. This was a decent enough result from a TN Film panel, but not quite as good as some other models we have tested.

 

Colour accuracy was also corrected quite well, with average dE now only 0.6. LaCie would consider colour fidelity overall to be excellent. Maximum dE was only 1.4 leaving only a slight difference between requested and displayed colour in greens and yellows mainly. If you don't have access to a hardware colorimeter, you can at least try our settings above, along with our saved ICC profile generated during the process.

 

I tested the screen with several colour gradients, which showed no obvious banding or other issues. You could spot some slight gradation across the range, and if you looked very closely you could detect the Frame Rate Control, which causes a very slight flickering up close. Not at all obvious in normal use though as with most modern FRC mechanisms.

 

I've plotted the colour accuracy results of the 2233RZ against some of the other 22" and 24" monitors we have tested here. Default dE average was somewhere in the middle really, and not too bad compared with some of the models. Calibrated dE average was joint second at 0.6 in the 22" models, being beaten only by the HP LP2275W which recorded 0.3. The other 22" models we have tested above are all TN Film based like the Samsung, with the exception of the HP which features an S-PVA panel.

Calibrated black depth (0.16) was very good here, beating the IPS models such as the HP LP2475W (0.17) and NEC LCD2490WUXi (0.19). It was also superior to the other TN Film based 22" models such as the LG L227WT, ViewSonic VX2245WM and Acer AL2216W. It was in fact, only second to the HP LP2275W here, which offered a calibrated black depth of 0.14 cd/m². Another respectible performance from a TN Film panel.

 

Contrast Stability

The range of luminance control from the panel electronics is actually very good here, and you can adjust the screen from it's default 220 cd/m² setting (at 100% brightness) down to about 64 cd/m² (at 0%). If nothing else, you are probably going to want to adjust your screen to around 35 - 40% brightness to achieve a comfortable luminance close to our target of 120 cd/m². While adjusting the brightness control, the black depth is improved as one would hope, and as such, contrast ratio remains pretty stable across the range from 100 - 0%. At the lower end, contrast ratio drops a little, but anywhere down to about 10% brightness setting should afford you a decent contrast ratio of around 920:1.

The results were plotted on the above graph to show the contrast ratio as you adjust the brightness control. There is no dynamic contrast ratio control on the 2233RZ, so something to note if you want that kind of feature. Personally, I don't miss it one bit.

 

Viewing Angles

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

The 2233RZ uses a TN Film panel, and so viewing angles are pretty much what you might expect. Horizontally, they are not too bad, but you do begin to notice an obvious contrast and colour tone shift as you move about 45� away from a perpendicular reference point and beyond. A yellowish tone is introduced once you reach past these angles horizontally, but in practice, you're unlikely to need to use the screen from this type of position.

Vertically, the viewing angles are more restrictive, particularly from below. At even a slight angle below a central point, a green tinge is evident, which can be distracting on white Office backgrounds. This was a little annoying actually, as you really had to make sure you were looking head on at the screen, of even from a little above. The green hue is more obvious the further down you move and the panel shows the characteristic TN Film darkening from extreme angles which you can see in the photographs above. From above, there isn't really a colour shift, but contrast does change at even quite slight angles. Average TN Film viewing angle behaviour here, so if you need more, you need to look for some VA/IPS based models really.

 

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.

The overall uniformity of the 2233RZ was very good here, with only really a slight difference in luminance along the left hand edge of the screen. Here, the luminance ranged down to 106 cd/m² as a minimum (13.2% difference from the target 120 cd/m²). Highest luminance was only 127 cd/m², only 5.5% difference. Pretty good overall really.

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

As usual, I tested the screen in a darkened room, showing an all black background. The above image was captured by my camera. You can actually detect some slight leakage of the backlight at the top and bottom of the panel which was a shame. This is particularly noticeable when viewing DVD's and movies with black borders top and bottom. You can also detect a little leakage from the four corners. Not the best performance, but nothing too severe to be honest.

 

Office and Windows Use

The Samsung 2233RZ offers a fairly modest, by todays standards, 1680 x 1050  resolution. This is pretty good, but I did feel the difference coming down from the 1920 x 1200 screns which seem to be far more common place nowadays, and used in my day to day work. Some 22" panels do offer this higher resolution as well, so maybe worth considering if you want more work space for office applications, especially for side by side viewing. The text quality was very good, and the DVI-DL offered a nice crisp image. There was no D-sub here to make comparisons. Once calibrated, the screen provided a comfortable luminance setting for prolonged use. The "text" MagicBright preset was a little warmer than our calibrated profile, but maintained a pretty similar luminance. If you don't want to calibrate your screen down to 120 cd/m², you may want to use this preset for office use. The "Internet" preset was very similar to the "Text" mode, a little warmer than our calibrated custom profile, but a little brighter than "text".

 

Responsiveness and Gaming

The Samsung 2233RZ 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.

3ms G2G TN Film - 60Hz mode

2ms G2G TN Film

6ms G2G S-PVA

6ms G2G AS-IPS

I'll talk first about the pixel response time of the 2233RZ before we come on to the exciting 120Hz feature. The screen features a 3ms G2G rated TN Film panel, a technology commonly used in the faster screens and the preferential choice of manufacturers making gaming screens. Oddly Samsung seem to suggest the 3ms G2G response time is applicable only in 3D mode, and in 2D mode you are limited to 5ms ISO response time. I'm not sure where this comes from, but you can tell in practice that the RTC technology is being used even in 60Hz (i.e. 2D) mode.

The G2G (grey to grey) response time quoted here indicates the use of Response Time Compensation (RTC) technology, helping to boost pixel transitions between grey tones. The response time of the 2233RZ as captured in this test was very good, with no discernable ghost image behind the moving car in the best case image. There was a slight dark trail behind the moving car, which was just detectable to the naked eye as well. This indicates an overshoot of the RTC impulse, causing the pixels to change beyond the required orientation, before dropping back down to the appropriate position. This is an artefact common in RTC enabled screens, and the resulting dark or light trails can be seen on most screens that use such technologies. In other models, such as the LG L227WT shown here for example, the trailing is pale in colour, which is arguably more obvious in regular use than a slight dark trail. All in all, the response time of the 2233RZ was very good and remained one of the faster screens we have tested.

 

120Hz Technology

Now on to the interesting feature of this screen, the 120Hz mode!

Selecting 120Hz mode was very easy, and the option was available via the menu of my graphics card. You simply select the new refresh rate and away you go. The difference was quite pronounced, with an obvious improvement in motion smoothness detectable, even in Windows applications. Movement of the mouse and browser windows seemed more smooth for a start. The motion certainly felt better, and testing the 120Hz mode with PixPerAn also revealed some pleaseing results:

The movement of the car overall was smoother, and you could tell the image was improved. What was also very pleasing was the improvement in the RTC overshoot. The black trailing behind the moving image was gone, and any sign of noticeable RTC artefacts had disappeared. If you looked very closely, you could sometimes detect a very slight dark trail in some circumstances, but as you can see from our 'best case' image, the results were signifacantly improved.

It's important to realise a few things here in relation to 120Hz mode. Firstly, the extra 60Hz does not alter the response time of the panel, since the operation of the pixels and their electronics remains unchanged. The 3ms G2G response time quoted by the manufacturer remains the same, regardless of which mode you are in, but is still very respectable in term of pixel response times.

The thing which many hard core gamers craved from an LCD screen was the ability to increase the refresh rate of the screen, that being the refresh rate and frame rate which the graphics card outputs to the screen. The refresh rate of your graphics card determines the rate at which the image is sent to the screen, and determines the number of frames which can be sent to the display at any one time. You will recall from the early days of CRT screens that setting a particular refresh rate on your graphics card would cause the image to be redrawn in a sweeping motion by the cathode ray gun across the display. Setting the screen to 60Hz caused the ray gun to re-draw the image 60 times a second, which is commonly referred to as the frame rate. In pratice setting a frequency of 60Hz on a CRT would lead to a flickering of the screen and often to user headaches. Settings of 100Hz or more were desirable as better screens became available, and it became one of the key considerations for choosing a good display. This was even more important to gamers, who wanted the possibility of sending larger and larger frame rates to their screen to improve their gaming experience and hone their skills in situations where a few hundredths of a second counted.

With the arrival of main stream TFT displays, we saw a change in how refresh rate was perceived in desktop displays. Traditional screens could take a maximum refresh rate of 75Hz, and manufacturers recommended instead a refresh rate setting of 60Hz. LCD displays do not operate in the same way as a CRT, and there was no cathode ray gun re-drawing the image at a certain rate. Instead, refresh rate ws quickly forgotten by many users, and they became far more focused on the pixel response time. This was after all the key indicator of how quickly the display could respond to changing images. Hard core gamers mostly dismissed TFT displays in the early years since the response time was not adequate to avoid ghosting and blurring of the image, and they could not warrant the move away from their trusty CRT. As response times improved over the years, and ghosting and blurring was significantly reduced, more and more gamers began to adopt the new generation of TFT screens. There still remained some gamers who did not want to make the move, but this was due to another reason, something that had been a driver behind changes in CRT screens - refresh rate. While the screen did not suffer from flickering problems set at 60Hz, it still remained a problem that you could not really send more than 60 frames per second (fps) to the screen from your graphics card. No matter what the response time of the panel was, you were still limited by a frame rate in games of 60fps. Setting the screen to 75Hz allowed you to output a higher frame rate from your graphics card, but in most displays, this was interpolated down to a 60Hz frequency by the panel and interface chip, or the additional frames were simply dropped.

Now, with the arrival of 120HZ enabled monitors, this is no longer a problem! You can happily send up to 120fps to your screen now with models such as the 2233RZ, and the screen is capable of displaying them. This can only be a positive thing. We see higher frame rates available for gamers, smoother images and motion in day to day use, and even a reduction in the RTC artefacts to boot! As a quick note about the reduction in RTC artefacts, this seems to be related to the frame rate of the screen, which sends a new images to the display at twice the frequency of before. As the image moves across the screen, an artefact trails behind it due to the agressive overshoot of the RTC impulse. The next frame sent to the display causes the image to update and the pixels change again. In 120Hz mode, the time between each frame being sent is half that of at 60Hz (i.e. twice as many frames per second). As a result, the trailing image is reduced by half, and the moving image is refreshed at twice the speed. In practuce this eliminates nearly all of the RTC issues common at 60Hz.
 

3ms G2G TN Film - 120Hz mode

6ms G2G AS-IPS

Above shows a direct comparison between the Samsung 2233RZ and our reference monitor in this test, the NEC 20WGX2. The 60Hz mode had some obvious RTC artefacts which left it a little behind the extremely impressive AS-IPS based NEC. However, with 120Hz enabled, and the RTC errors greatly reduced, I think we have a new reference monitor! This is the fastest model we have tested to date, and the best we have seen overall in terms of response time, RTC errors and of course now, frame rate.
 

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.

As you can see from the results, the Samsung 223RZ performed well here. Input lag did range from 0 to 30ms in our tests, and averaged out at 15ms. This was similar to some of the popular models such as the NEC 20WGX2, and other 22" models we have tested like the Acer AL2216W and Viewsonic VX2245WM. 15ms was a respectable performance and you shouldn't see much, if any, delay in your gaming here.

 

Movies and Video

The following summarises the Samsung 2233RZ's performance in video applications:

• 22" screen size intermediate for movie viewing. Larger screens are far more common place nowadays, so 22" could be considered quite small

• Widescreen aspect ratio does lend itself to videos and movies

• 1680 x 1050 resolution is enough to show 720p HD content, but is not enough to show a true 1080p HD image, which requires a resolution of 1920 x 1080.

• Fast response time excellent on the 2233RZ, meaning no ghosting and very minimal motion blurring in fast moving scenes

• 120 Hz mode helps reduce overdrive artefacts, and adds a smooth feel to movement on the screen

• Decent black depth (0.16) helps ensure detail is not lost in dark scenes. Contrast ratio is good

• Standard sRGB colour gamut means colours do not appear oversaturated or too neon

• Panel uniformity is not perfect, and there is some leakage along the bottom and top edges which could prove distracting during movies with borders

• TN Film panel technology means viewing angles are unfortunately quite restrictive, especially vertically. This does not really lend itself too well to movie viewing. You will want to be aligned head on to view the screen, and it's not really suitable for multiple viewers.

• There is only a single dual-link DVI interface on this screen, so it is no good for connecting multiple external devices or games consoles.

It should be noted that the 120fps cannot really be taken advantage of with videos in the true sense of the word. 120Hz technology can handle frame rates of up to 120 frames per second (fps). In some modern games, your graphics card is capable of out-putting a frame rate at this level, giving you smooth game play and rapid changes in the image being shown. Movies and videos typically operate only at 24 fps however and so you won't be in a position to take full advantage of 120Hz in this use.

However, although the content itself does not operate at more than 24 fps, the graphics card is still sending an image to the screen at 120Hz. You should therefore benefit from reduced RTC errors as we saw in our response time tests. Movement on the screen still feels smoother, and you may find it smoother if you look very closely during movies. Operating at 120Hz also has the advantage that the frame rate (24 fps) fits perfectly into 120 fps by a division of 5 (i.e. 24 x 5 = 120). This can sometimes help offer smoother images and less frame dropping or stuttering in playback.

It should be noted that LCD TV's operate in a different way when they offer 120Hz (or even higher) modes. Since LCD TV's are not in a position to be provided with a frame rate higher than 60fps really, being used primarily for TV signals and DVD's, they achieve their "120Hz mode" in another way. This is done by frame interpolation, whereby the 60Hz signal is interpolated internally by the TV electronics, and intermediate frames are estimated and caluclated to increase to 120 frames. This can help improve smoothness and reduce blurring, but it is not accepting a true 120Hz signal from any source and every other frame is in effect being made up. This is an effective technology in modern TV screens certainly, but operates differently from the 120Hz mode in the Samsung 2233RZ.

 

Conclusion

Samsung have done an excellent job here providing an excellent LCD screen for gamers. The screen offers a very decent response time, limited RTC arefacts, minimal input lag and even comes with a new 120Hz support mode. Take all of these into account, and you have yourself one hell of a gamers TFT! The 120Hz undoubtedly has its place in the desktop monitor market, and should take one giant step towards pleasing those hard core gamers out there who need and want frame rates which just couldn't be offered before. The technology has a marked improvement in even day to day use, but when gaming will certainly come into its own.

On top of this, the TN Film panel does offer a decent black depth and colour reproduction, but is only really limited by its poor viewing angles. The screen is fairly standard in design and features, but could be considered a pure gaming screen without too many bells and whistles. It will be exciting to see the inclusion of 120Hz on more and more screens in the future, and we look forward to the emergence of 120Hz enabled IPS and VA panels, and the inclusion in high end screens across the market. Until then, if you want a good gaming TFT, look no further than the 2233RZ.