|Originally posted by Rzk
Great, more confusion.
Now I am hearing some of these LCDs cannot display a full range of color? What tha...
I am currently using a Samsung 191T with my desktop. Does anyone know which LCD for the 8890 and/or the 5680 comes closest to the Samsung in visual quality?
Firstly with your 191T - Great screen - I tested out one the other day. You can check out my comments about it here
. Bottom line the Samsung 191T connected via the 8890 DVI output is a great match to the 8890 screen. (Envy, envy - I want one btw).
If you put the 191T and 8890 side by side the screens are almost identical.
As to the so called blotchyness on the 8890, I found once I had configured everything properly the blotchy effect disappears totally (remember the bliss wallpaper has artifacts in it that all top end monitors will pick up - this is not related to the blotchyness). The 8890 screen is marginally better than the 191T screen imho.
After checking out the specs again on the 5680 I found that it only supports 262K colours, not the 16M of the 8890 screen. This assumes the 5680 screen is the IDTech/IBM LCD.
Coming back to the blotchyness I discovered that the effect is due to the way M$ encodes its shading in the IE bar (and others). What happens it that they specify a gradual colour shift by a JPEG image. Like all JPEG encodings it is lossy and prone to artifacts as the image is redisplayed. The ATI drivers are just doing the correct job as specified by the JPEG image. The only improvement that you could ask for is that ATI somehow ramps the colours within a colour block, blending from edge to edge in a gradual colour variation. This would ground even a 3.2 GHz CPU trying to do all the decoding. Note this has to be done by the CPU initially - it is not a GPU shader job because the GPU knows nothing about JPEG images. You might be able to use a shader in the GPU to help but ultimately it is the CPU doing the JPEG decoding work.
Now 8890 owners - if you want to prove that it is NOT your LCD or system causing the blotchyness but rather the way M$ is encoding its images do the following:
1. Open the file C:\WINDOWS\system32\oobe\images\newmark8.jpg using the Windows Picture/Fax Viewer (it should default to this anyway).
2. Make sure you are in 32 bit colour mode
3. Open Control Panel -> Display -> Settings -> Advanced
This will bring up the ATI panel.
4. Select the Colour tab.
5. Set Gamma to 0.50
6. Set Brightness to -50
7. Set Contrast to 180
Now have a look at the blue banding present. This is the same effect as the blotchyness (you might be able to see it happening on your IE bar under these settings). If you zoom in to the top left hand corner you can see the effect quite dramatically. If you then move the viewer window you will notice the blotchy effect moves. This shows the LCD is NOT at fault. If it was the blotchy effect would stay in one place when you move a window. Nor is it the ATI drivers fault. It is caused by the way JPEGs are encoded and then decoded. If you built a really clever JPEG decoder you might be able to get rid of the artifacts by blending edge to edge across the artifacts but as I pointed out your CPU would get really busy just trying to create the pixels.
The IE grey bar is also a JPEG and it contains colouring splashed across it in the form of tiny blocks of JPEG compressed artifacts. These tiny block are what you see on your high performance 8890 LCD. You can see it on a normal CRT if you play with the brightness etc.
The inverse of all of this is get a super high res jpeg (>2 MB or better still a bitmap (.bmp) which does not suffer from losses like JPEG) particularly one with large areas of graduated colour. Display it on your screen and adjust the settings again. You will not be able to see any blotchyness.
Bottom line for anyone with an 8890 first do some thorough research on the issue, then double check your findings. If you are getting the blotchyness check your LCD settings. (Also check you have not set a theme that uses a funny background either).
For anyone worried about the 8890, don't be. The LCD is probably the best LCD in the world right now. Go and check out the Samsung 191T in a store - it is comparable to the 8890.