Explain this phenomenon

[Mesmerist]

(To the moderator) I fail to see how my post does not belong here. Had you read it in its entirety, you should have realized that I was not asking for support on anything. There is no trouble to shoot! Quite to the contrary, I am attempting to find someone extremely knowledgable in graphics and rendering who might go into some detail on the phenomenon I describe, in hopes of sparking a highly technical discussion on the subject. Browsing the topics listing leads me here, as the type of person I am looking for would be most likely to browse the highly technical forum. If you deem it appropriate to lock my thread again, at least grant me a specific reason and/or suggestion on where it belongs. I would appreicate it.


So, let's try this again...

Hello all. I'm lookin for input on a question that I find myself unable to answer. If anyone has any pertinent information to contribute, I would appreciate it greatly!

I have a friend who has a decently-equipped gaming rig, sporting an Athlon 2100+, 1GB DDR RAM, ATI Radeon 8500, etc. In many of his games, the framerate increases when he raises the resolution. For example, increasing the framerate in Tribes 2 from 800x600 to 1024x768 results in a net gain of 15-20 FPS. The same thing occurs in other games, such as Jedi Knight 2. Furthermore, enabling extra graphical features such as trilinear filtering, hi-res textures, and volumetric fog tend to result in a framerate increase as well. When we bump these setting sback down, sure enough, the framerate goes back down too. We popped in a GeForce 3 Ti500 and the same thing happened. Not that this is a bad thing, but it does raise an interesting question (to me, at least). How can this be? My friend came to me since I know a fair amount about computer hardware, but I couldn't help him. Can you help me answer this one? Thanks guys!

To answer stebesplace's question(s), I do not think any of the games offer software rendering as an option. I could be wrong, but isn't software rendering practically obsolete in modern 3D shooters and action games? This phenomenon can be reproduced in virtually any recent game.

Again, I'm just looking for technical information/explanations. There's no problem to troubleshoot here. Thanks again.

 

[Yomicron]

what refresh rates is the computer using at each resolution?

If at 800x600@85Hz will max out your FPS at 85 and if 1024x768 is set to 100Hz, it is possible to notice an extra 15fps, assuming the rig is able to generate >100fps.

 

[Sahakiel]

Two words for you: Driver tweaking.

 

[Shalmanese]

I dont think its anything to do with drivers or whatnot. He seems to have a fairly standard rig and this kind of thing is just odd. I dont think its to do with monitor refresh issues either since turning on volumetric fog and trilinear seems to also increase frame rates. Hmm... my guess is either your friends BSing or you have an uber l33t computer.

 

[Weyoun]

I agree with Shalmanese on this point - this is not ONLY a refresh rate issue. however, I do suspect that it has something to do with his driver config. The only possible way of increasing the framerate in an application is to either reduce the number of steps per cycle or shortening the length of time it takes for those steps to perform their associated operations. stebesplace's hypothesis seems to be the most likely, though I fail to see how it could apply to the resolution changes since the workload is only increasing. The rendering path hasn't been changed. In order to effect the observed increase and, assuming that the only effect of increasing the resolution was the change the number of rendered pixels on the screen, either the number of cycles per second MUST have been increased, or the time of the rendering step MUST have decreased; clearly the latter case cannot be true, since increasing the number of pixels being rendered by the SAME path would only serve to increase rendering time. We must therefore conclude that your framerate increase is a direct result of a refresh rate difference, a change in rendering paths, or as is highly likely (even necessary), both. The FPS increase on resolution change can only be explained in terms of a refresh rate difference, and the addition of extra features can only be explained in terms of a changed path. Even though enabling an extra feature in a game may increase the amount of overall calculation, we may find that the hardware accelerated (though more calculation intensive) path is vastly more efficient and even quicker in the long run compared to running a simpler process on a general CPU. A good method to prove the resolution argument would be to enable super-sampling antialiasing (do nVidia even offer that mode these days?), as it would increase the pixel throughput without changing the screen resolution. If you still see a framerate increase... how much are you willing to sell your friend's computer for?

 

[Cogman]

,,, I hope you tried to contact the moderator first before re posting this, Doing something like this might result in a ban......

 

[Shalmanese]

On the off chance that the moderator reads my post, I wholeheartedly approve of this being in HT. its clearly not a troubleshooting issue and damn cool in the process.

Could you give a little more detail about the exact setup. Were you actually in the room when this was happening or did you only get told this by a friend?

Could we get you entire computer spec as well as some hard data to look at.

Run some standard benchmarks (ie. 3DMark, Q3 etc) at different resolutions from 640x480 to 1600x1200 and using different graphic settings. Run the benchmarks using standard benchmarking procedure (and make sure nothing unneccesary is running in the background, this is important) and detail you exact procedure.

If we cant find anything wrong, I'm sure your friend could sell his computer on ebay or in the FS forums for quite a hefty sum and could probably score a nice upgrade out of it .

 

[stebesplace]

SOftware rendering has been around since the before hand of the 3d card world. It was used as a primary for graphics, when there was no such thing as a 3d rendering graphics device. . .aka 3d card. SO. . .

Games these days, still offer software rendering since it is the MOST compatible with everyone's computer. I am not sure how it exactly should affect resolution as in going higher / lower, but one thought comes to mind. . .when running on lower resultion, your card actually is putting larger pixels on the screen. . .so, in theary, more area is needing to be rendered out per pixel, versus a smaller pixel size at larger resultion., Perhaps more data is needing to be pushed at a lower resultion. Its hard to say off hand, and I've never come accross this, since it is usually the oposite way around.

Here is my next question

Is this only a problem in DirectX or is it a problem in OpenGL as well.

If there is a problem with directX, make sure you have 8.1 installed and working, as well make sure that you have the most current drivers installed.

If you are running in OpenGL, make sure you have at least 1.3 installed, or your drivers new so it can support the 1.3 standard. 1.4 would be ideal.

Normally, this type of situation does not just happen. Something is wrong, along the pipeline somewhere. Make sure your ram is in good order to, also check to see that your processor is correctly configured in your bios. Are you overclocking?

-Steve

 

[SupermanCK]

couple of questions:
1) Did you test out the system?
2) When you change to higher resolutions, did the detail actually increased?
3) How about other system specs? like does temperature also increase? other unusual thing going on?

my hypothesis is that either but setting the extra stuff actually turns off the feature, like a reversed action. Just like when you increase resolution, you are actually decreasing it...somewhere in the software coding is reversed...
other than that...i can't come up with anything...

 

[dejitaru]

It may be optimized for higher resolutions, leaving the support lower detail neglected.

The GeForce 3 actually runs faster in 32-bit than in 16-bit color.

Perhaps mip maps were disabled.

 

[teqwiz]

The only way it I can think how this might happen is if default settings for higher resolutions were to revert to compressed mode and 16 or 32 bit in the lower resolutions. Your friend would have to set this up himself as far as I know though, and would already know the answer to his own question, unless he did it by accident while playing with the settings, so that hardly seems likely. What operating system/driver combo? I would think that optimized newer drivers and an older OS might produce this anomoly. Find out his specs and settings in Tribes 2. I'd love to use his config if it's possible.

 

[Mesmerist]

Thanks for all the great feedback so far guys! I'll try to answer some of your questions.

Yomicron: Well, in Windows the refresh rate is simply set to Adaptor Default. I can't tell you much more about the refresh rates he is running. Is there a way to see specific refresh rates while running in the game? I remember seeing a monitor that had an option to show refresh rate every time a game or app changed resolution, but I'm sure his monitor doesn't do that.

Weyoun: Heh, for $5K I will go over to his house, steal the computer, and sell it you right now! He'll get over it.

Cogman: Yeah I thought about that possibility. But, honestly, it wouldn't be any skin off my back if I got banned. Perhaps then I'd be more apt to go finish my research paper?

Shalmanese: Thanks for your support. At first glance I can see how my post might look like a troubeshooting issue, but, as I said, there is no trouble. In fact, most people would love to have such a "problem"! And it's not BS... I saw it. It's nothing that would blow you away, but it's intruiging enough to provoke one to start a thread about it here. I'll try to get him to run 3D Mark and I'll see about getting a copy of his dxdiag txt. That should contain all the hardware info you might need.

stebesplace: I'm positive that this was the case with OpenGL. I'll have to double check with him about Direct3D... I feel fiarly sure we tried D3D though. And he did reinstall the latest DirectX... no problems there.

SpermanCK: I played with the system briefly. Yes, increasing the resolution under the video settings did physically alter the detail on the screen. For example, the in-game text got a bit smaller, as is common with resolution increases in games.

dejitaru: You are thinking along the lines I was thinking. I know newer cards are optimized for newer graphical features and rendering techniques and I remember reading an Anandtech article or two in the past which mentioned such a phenomenon (performance and graphics co-scaling upward). Unfortunately, it's been a long time and I can't remember which article(s) it might have been nor any specifics. But, it was basically saying that some parts of the GPU weren't being utilized with certain graphics options disabled and that by enabling these features performance would increase as more of the GPU was being put to work (if that makes any sense!).

Again, thank you everyone for your this thought-provoking discussion.

 

[wolf papa]

Is anti-aliasing enabled ? Is it possible that the drivers or even the game are reverting to lower quality settings or disabling some features in order to maintain frame rate?

What OS is being used?

 

[Mesmerist]

Well, I believe he said that the framerate increased a tiny bit when he enabled anti-aliasing.

He is running WindowsXP Home Edition.