Of refresh rates, fps and CF-settings "IN Game"

Ok, I cant seem to find all information relating to these in one place. In order to help anyone else who's new to all these technicality and myself as well, it'll be nice to put in "fps" related "in game" questions to the experts here.

Please note that no question related to benchmarking tools will be asked here. There's a seperate thread for that. This is purely intended for "In Game" performance discussion, differences between games and their fpss etc on the M17x ofcourse

Here are the first set of questions for the experts
1. Whats the co-relation between refresh rate of your display and fps in game? Does the fact that the RGB LED screen's refresh rate is 60 hz imply anything in this regard? Why does the fps sometimes seem capped at 60 on the m17x when video card review sites often report ridiculous fpss of 150 plus?

2. What kind of FPS can you expect from playing a game like UT3 or Crysis on the CF 5870 and the single 5870?

3. What are the optimum settings on the ATI catalyst Control center regarding the AA, AF, etc?

4. Does efficient cooling give you an added FPS advantage?

5. How much IN Game performance is GPU related? which are the games which rely more on the CPU than the GPU?

6. Are there any games so far that you cant play on the highest settings on the M17x (average config - for eg i7 720, 820, CF 5870, 4 GB ram)
If so, which are those games?

 

1. It helps here if you basically understand what a screen refresh rate is. Basically, any screen (be it a TV or the RGB LED screen in your M17x) refreshes the picture a certain number of times a second. In this case, 60 times a second-60Hz. Most screens and TVs run at 60Hz, some run up to 120Hz (or 120 refreshes a second).

This does come into gaming though-if your framerate was, say, 45, your screen is still refreshing at 60 times a second. It'll only change the image when it's got a fresh one from the GPUs to show. This means the display frame times will sometimes be longer. It's not a noticeable, significant change though.

Where it becomes more important though is when the frame rate is above the screen's refresh rate. If you're getting above 60fps on a 60Hz screen, that extra FPS is wasted. The screen can't change images that quickly. So, essentially, you can only see 60fps, no matter what your computer pushes out.

This is where 'vsync' comes into play. It locks the maximum FPS to the screen's refresh rate-in this case, it'd be locked to 60fps if vsync was on. This has two main advantages; it can fix any image tearing, and it can also lower GPU temps where the GPU would be uselessly rendering extra frames.

2. I can't say for sure, I don't have one. Both GPUs should monster any game using the Unreal engine. Even with a single 5870, the Unreal engine is easily handled at high detail levels and resolutions close to 30fps.

As for Crysis, I'd expect average 30-40fps on a single 5870 if you were maxed out on a low resolution (1024x768 and the likes). Add the second 5870, you should manage the same at 1920x1200. It won't give you much advantage at lower resolutions as Crossfire scales better at higher resolutions. In fact, at 1024x768, you might see no advantage at all from Crossfire.

3. Well, the fastest settings are to turn AA and AF off completely. Basically, set them in the control center to use in game settings, and don't put them on in game. If you're running at a high enough FPS, bring AA and AF on.

4. No. The only case where cooling will improve performance is where your computer is actually throttling performance backwards with overheating, absolutely NOT an issue in the M17x. On the other hand, better cooling can give you better overclocking headroom-but this is only significant on the GPU in most games, which is very difficult to overclock.

5. The GPUs are the single most important components in any game. No game will run well with superfast CPUs but poor GPUs. The ONLY case where the CPU comes into play is when the CPU is bottlenecking a game, so the GPUs can't do all their work.

Nearly all games out there are far more GPU heavy than CPU. However, some run much heavier on the CPU. In particular, real time strategy games are known to require a powerful CPU.

6. Can't answer it, I don't have it. However...with crossfire 5870s, there shouldn't be a single game out there that can't run maxed out, even Crysis can.

 

Thanks for the reply! I just tried out many of the things that you mentioned. Just one thing that I'm not sure of is this..
While playing UT3, I was getting a steady fps of 60fps on 1900-1200 resolution with all options in game turned on to highest and Vsynch turned on. However, once I jacked up the AA and AF in the Catalyst Control centre, the fps dropped to around 26 - 39. Is that normal?
Then I set the CCC settings to default and then turned off Vsynch. Going by the information i have, i was expecting to see a smoother performance since now there's no limitation on the fps rendered by the GPU. However, I found that turning off Vsynch resulted in lesser fps than turning on Vsynch! is there any reason for this?

 

Some games and some graphics cards seem to work better with vsync on. I'd recommend turning on triple buffering as well, there's an option for it in the control centre. It can give another fps boost with vsync on too.

It's expected that FPS drops massively with AA and AF jacked up. AA basically cuts out jagged edges, and AF increases the quality of the textures. Both will incur a significant FPS hit if turned all the way up.

AA maxed out is usually a waste of FPS. Try AA just on 2x, and AF all the way up. Mix it up a bit.