Resolution question and other questions

[TheCommander]

How much more harder does a video card have to work when you go to a higher resolution?

I was wondering this because I've been getting some artifacts (blinking white dots) when playing Neverwinter Nights 2. I have an ATI 4850 and am running the game at 1680x1050.

Would lowering the resolution or some other setting that is vid card intensive solve the problem?

On a side note, do AA and AF rely on the CPU or the vid card?

 

[kllrnohj]

artifacts means there is a problem, not that the card is working too hard. It usually means the card is clocked too high if you have overclocked it, or it is defective. Do the standard re-install of drivers to make sure it isn't a driver problem, then RMA it if you haven't OC'd it

AA and AF are both on the video card.

 

[necrophile]

Don't want to sound an arse, but why are you asking if lowering the res would solve it, just try it out and see.

Also, it could be a defect as mentioned above but perhaps you should turn up the fan speed a bit and see if that helps.

Also, how many other games does this happen in and have you tried something like atitools artifact test or something similar?

 

[[H]adouken]

How come on some benchmarks, I'll see the high-end cards perform at higher framerates at higher resolutions? Is it a bottleneck thing?

I tried searching for proof, but now they're all gone. They all seem to be showing better frames at lower resolutions -_-. Hold on...

 

[n00zler]

Lower resolutions rely more heavily on the CPU, higher resolutions more on the GPU. When your CPU is a bottleneck, you sometimes hit a point when dropping the res reduces the stress on the GPU but increases it on the CPU, meaning you get lower framerates. Weird, I know. Thats also why you'll often see benchmarks for SLI systems that have the lower res tests all at the same framerate. Until they get up above the point where the GPUs aren't being pushed that hard, the CPU is capping the framerate, not the other way around.

 

[TheCommander]

Don't want to sound an arse, but why are you asking if lowering the res would solve it, just try it out and see.

Also, it could be a defect as mentioned above but perhaps you should turn up the fan speed a bit and see if that helps.

Also, how many other games does this happen in and have you tried something like atitools artifact test or something similar?

The problem only occurs in NWN2. It also seems it was a heating issue. I did turn up the fan speed but the fan is insanely loud now. I guess the ATI auto fan control was not doing what it was supposed to.

 

[TheCommander]

Lower resolutions rely more heavily on the CPU, higher resolutions more on the GPU. When your CPU is a bottleneck, you sometimes hit a point when dropping the res reduces the stress on the GPU but increases it on the CPU, meaning you get lower framerates. Weird, I know. Thats also why you'll often see benchmarks for SLI systems that have the lower res tests all at the same framerate. Until they get up above the point where the GPUs aren't being pushed that hard, the CPU is capping the framerate, not the other way around.

How is that so- wouldn't it be easier for the card to run a low res?

 

[n00zler]

Its too easy for the card, thats the thing. The CPU has to push the frames to the GPU, but it can't keep up with the GPUs at the low res. At high res, the CPU can push more frames than the GPU can handle.

 

[kllrnohj]

Lower resolutions rely more heavily on the CPU, higher resolutions more on the GPU. When your CPU is a bottleneck, you sometimes hit a point when dropping the res reduces the stress on the GPU but increases it on the CPU, meaning you get lower framerates. Weird, I know. Thats also why you'll often see benchmarks for SLI systems that have the lower res tests all at the same framerate. Until they get up above the point where the GPUs aren't being pushed that hard, the CPU is capping the framerate, not the other way around.

dropping the res should never increase the load on the CPU, that doesn't make any sense. The work the CPU is doing is independent of the graphical settings. Increasing the resolution will never increase the frame rate on single GPU systems (outside of a margin of error, of course)

Its too easy for the card, thats the thing. The CPU has to push the frames to the GPU, but it can't keep up with the GPUs at the low res. At high res, the CPU can push more frames than the GPU can handle.

Yes, but all you are doing is shifting the bottleneck. If the CPU can push out, lets say, 50 FPS but the card can render 100 FPS at resolution A, then you are going to be CPU limited at res A at 50 FPS. If, however, you increase the resolution to B and the card can now only render 40 FPS, you are now going to be GPU limited at resolution B and only get 40 FPS. The CPU is therefore doing less work because it is only pushing 40 FPS, not its max of 50. You won't see an increase in FPS by increasing the resolution for single GPU cards (SLI/CF have other issues)