Timsh

Im wondering but what part of the games like FEAR/cod2 etc are cpu limited? What does the cpu do in games/ ai? and why people say at higher res and higher AA/af cpu limitation goes away or limits it? by how much? fps?

Say i play at 1024 res no aa/af and i have a cpu of 2.2ghz intel. So im cpu limited.? If i change to 1600res all AA/af how much a difference would it be?

daedal

CPU limited would be, say, running a 7800GTX on a PIII 1.0ghz.
Although the video card is very fast, the CPU can't keep it and lags down the whole system rendering the video card's potential untapped.

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Timsh

Yea but.. like i said

What does the cpu do in games


why people say at higher res and higher AA/af cpu limitation goes away or limits it? by how much? fps? how?

I already know the basic part about it

Nacht

in games, the cpu usually does the loading work, as well as AI computations. Also, if there are generated environments, it can handle that too.

However, the CPU's main responsibility while gaming is to feed the video card with information. When you hear the term "CPU Limited", it means that the CPU is unable to feed the video card information as fast as the video card can handle it.

EDIT:

Oh, just read your second paragraph.

when you turn up the resolution/AA/AF, it doesnt make the system less cpu limited...it's just that those three filters all take place on the video card itself, regardless of the CPU. No matter what these settings are on, the CPU always sends the same information (textures, verteces, etc), and the video card applies these effects afterwards.

Timsh

how can you tell if you are cpu limited? some tool u can run ? something to look in a game?

mkk

If a game does not perform better when the graphics resolution is lowered, then you can safely assume that in that perticular game at those perticular settings the CPU is what is holding you back. Wich means that you might just as well raise the workload for the graphics card a little by increasing resolution or effects.

Timsh

So say you load up bf2 or any game

Record fps at a certain point with 1600 res 4aa then lower res to 1024 res at that same point and get no gain in fps or very little 3-5fps.. That mean you are cpu limited?

No_Style

Bingo. It's also worth noting that certain games are more CPU limited while others aren't. Quake 4 (Well almost any id software game) is more CPU limited. Here's an example of CPU limited it taken from X-Bit Labs. Notice how regardless what video card is being used, the difference is marginal. F.E.A.R. on the other hand is the exact opposite.

Games can also be CPU limited, despite the fact that they rely heavily on the video card. This only occurs if a PC is just ridiculously slow in terms of CPU power. (Pentium 2 233 MHz and X1900 XTX and F.E.A.R.). In your specific case, you may be CPU limited for all of today's titles, even if they rely heavily on the video card. (I'm not entirely certain, but it could be the case).

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