Spike_UK

I've noticed a problems with the last few Catalyst driver releases that's starting to bug me.

I use a Hitachi CML174SX TFT Monitor, which is fantastic for games ect. But lately I've been suffering a problem with non-native resolutions.

Basically, it appears that there is something in the current set of Catalyst (3.10) that is stopping my TFT screen from using the Non-Native Smoothing Algorithm. I'm not sure when this started. But from my memory I belive this has been present since Cat 3.8 onwards (definatly present in 3.9 and 3.10).

I belive this a Catalyst issue as everything is OK using WinXP's Standard VGA Driver.

Because TFT's do not use the 4:3 aspect ratio (1280x1024 isn't 4:3, 1280x960 is). So when you run at 800x600 the TFT resizes the image to 800x640. THis results in what I call "Pixel Stretching". To compensate for this a Smoothing Algorithm is used to smooth out the image. The reason I can see display corruption (pixel streching) is because the Algorithm isn't working. If you too can see this corruption then you are also suffering this problem.

As this only effects the screen, it's very hard to give an example. The best I can do it replicate the problem using Photoshop.

To replicate the problem in Photoshop, just take a 800x600 image and resize it to 800x640 without any Bilinear filtering.
To see how it should look, take the same 800x600 image and resize, this time using Bilinear filtering.


Below is a rough example (it's alot worse in RL) of the display when using Non-Native Resolutions.



And this is what it should look like




Basically, the picture quality hasn't decreased in the driver revisions, it just appears the there is something that has been done to the drivers that is stopping the Smoothing Algorithm from working.

It might not be something IN the drivers, but it's definatly something related to installing the Catalyst drivers as everything works fine with the standard Windows XP drivers. It only happens AFTER Catalysts have been installed.

I've asked this question on Rage3D but have received no real answers.

Any ideas lads?? It's realy annoying not being able to play games that use Non-Native Res

dipstick

Not sure about this, but have you tried going to Display Properties/Settings/Advanced/Displays/Select your monitor and uncheck the 'Scale Image To Panel Size' option. You'll get a black border on non-native resolutions, but at least it won't stretch the image.
Hope it helps

Spike_UK

Yes I've tried that Option...that works for all Non-Native Resolutions APART from 1024x768 and 800x600. Those two resolutions ALWAYS use the full screen, even if that option is unchecked.

Something is b0rked

Spike_UK

OK, here's the lowdown from my morning of testing (Cat 4.1).

1280x1024 is fine in all regards. I am only testing Non-Native Resolutions (ones below 1280x1024).


Non-Native Smoothing Tests

1280x960 - Algorithm ON
1280x768 - Algorithm ON
1152x864 - Algorithm ON
1024x768 - Algorithm OFF
800x600 - Algorithm OFF


Non-Native Resolution Image Scailing (Option turned on in Catalyst Suite)

1280x960 - Scailing ON
1280x768 - Scailing ON
1152x864 - Scailing ON
1024x768 - Scailing OFF
800x600 - Scailing OFF


From these results I'd assume that the two thing MAY be related.

I have submitted the bug report to ATi.

Zardon

ill mention it to Chris Hook in ATI, ive forwarded him this information. he might be busy but I hope he can get time over the coming week to read it.

Spike_UK

Many Thanks