Guru3D.com Forums

Go Back   Guru3D.com Forums > Videocards > Videocards - AMD - ATI Drivers Section
Videocards - AMD - ATI Drivers Section In this section you can discuss everything Catalyst related. AMD Catalyst drivers are for all AMD ATI based graphics cards. This is also the place to discuss modified Catalyst drivers.


Reply
 
Thread Tools Display Modes
GPU Scaling, or Monitor Scaling?
Old
  (#1)
thechiweenie
Member Guru
 
Videocard: Sapphire HD 3850 512mb PCI-E x16
Processor: Althlon 64 3400+ Venice s754
Mainboard: MSI MS-7145
Memory: PNY Optima 2GB(1GBx2) PC3200
Soundcard: Audigy SE w/Logitech 5.1's
PSU: Sunbeam 580W
Default GPU Scaling, or Monitor Scaling? - 04-10-2008, 00:59 | posts: 57

Well I didn't realize the reasons my games where crashing was because of GPU scaling I had set, lol so now they are all set at 1920x1200... I just purchased a Gateway FPD2485W TFT LCD Monitor, lovely picture. And GPU scaling enabled by default, but the monitor has its on built in scaling also. So after thinking something was wrong with my computer, but finding that running a game in windowed mode and then setting to 1920x1200 closing and re-opening worked fine, I was dumbfounded. Then I realized I had GPU Scaling on, and when disabled I had no issues, so my question is two fold I guess! A) do I need GPU Scaling at all? and B) I have switched from Scale Image to full screen size to Maintain Aspect Ratio, I have been unable to test anything out to see if that worked because now all my games are at the proper res! But would Maintain Aspect Ratio work better I wonder?
   
Reply With Quote
 
Old
  (#2)
sdack
Banned
 
Videocard: ATI Radeon X850XT AGP 256MB
Processor: AMD Sempron 3000+
Mainboard: Asrock KN7NF RAID
Memory: DDR400 (Kingston HyperX)
Soundcard: Creative Audigy ZS2
PSU: Sharkoon SilentStorm 480W
Default 04-17-2008, 14:47 | posts: 148 | Location: England

By default you should disable GPU scaling just as you should disable everything else that is unnecessary. It, as you seem to have experienced, creates new areas of problems as well as can cause a loss in performance.

You then only use GPU scaling if your monitor cannot do any proper scaling for you and only should you do up-scaling of a low resolution. Down-scaling a high resolution to a lower one so that it can fit your monitor's actual size is a waste. Better set it to 1:1 and use anti-aliasing if you want to improve image quality.

How well GPU scaling works I do not know. Set your GPU's resolution to one that is just a little bit smaller than what your monitor can do and watch the difference when you enable GPU scaling. Some monitors are only capable of a dumb extrapolation, filling up every 2nd or 3rd pixel with the value of that of a neighbour. This will result in some thin lines appearing twice as thick and makes text almost unreadable. A better way is to do a linear extrapolation where the missing pixels get the average colour value of its neighbours. I doubt that any monitor or GPU will do a bicubic extrapolation which would result in an even better quality. If nothing works well you can try using an even smaller resolution for you GPU and see how well that does.

If you should keep the aspect ratio or not is then a matter of taste. Some people just seem to love it when scenes gets stretch or compressed only for the sake that it then fills their entire monitor. If you do that you probably eat fast-food that is 2 days old, too. In some cases a change in the aspect ratio can make the result of the extrapolation better as well as worse.

Sven
   
Reply With Quote
Old
  (#3)
AcceleratorX
Master Guru
 
AcceleratorX's Avatar
 
Videocard: GTX 560 Ti OC
Processor: Intel Core i5 2500K OCed
Mainboard: ASRock Z77 Pro4
Memory: Corsair XMS3 1600 2x2GB
Soundcard: Realtek ALC892
PSU: Antec VP550P
Default 04-18-2008, 23:10 | posts: 297

The GPU scaling function is done within the display pipeline AFAIK, and has no effect whatsoever on the 3D pipeline. So in general there should be zero performance loss, with the only perceivable difference being slightly extra GPU activity at idle or an extra degree in the temperature charts.

GPUs these days have specialized hardware to do scaling. AFAIK this involves the RAMDACs, and nowhere have I heard (and I have seen from personal experience as well) that using GPU scaling does not cause a performance loss.

In general I never faced any problems using this as well, but the setting is highly dependent on both your monitor and the drivers, so I wouldn't be surprised if someone was having problems.

Last edited by AcceleratorX; 04-18-2008 at 23:12.
   
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



Powered by vBulletin®
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
vBulletin Skin developed by: vBStyles.com
Copyright (c) 1995-2014, All Rights Reserved. The Guru of 3D, the Hardware Guru, and 3D Guru are trademarks owned by Hilbert Hagedoorn.