Explain GPU usage please.

[lwgnlseven]

Can anyone explain Gpu usage to me? When I play BF3, my CPU (i5 2500k) sits around 60-70% usage and GPU is at 99% usage, which is good. But now i'm playing F1-2012 and CPU usage is at 75-85% while GPU usage only at 65-75% usage. Why doesn't this game run at 99% usage? Isn't that ideal? Wouldn't I get more FPS out of the game if it ran at 99%? Another questions is why isn't running at 99%?

 

[PennySavre]

Maxing out a GPU only happens sometimes and is actually rare for a lot of games. Sometimes the GPU has to wait on the CPU or the CPU has to wait on the GPU. So in other words, your system is fine.

 

[BiggieShady]

CPU usage is calculated as average of usages of all cores.
Various game engines are usually multi threaded to various degree and various threads have various performance impact. For example rendering thread is very demanding (issuing massive number of draw calls and pushing frames as fast as possible) and audio thread is not very demanding.
Result is fluctuation of overall cpu usage.
GPU is different story, it's usage can drop if vsync is on (waiting for 60fps screen refresh) or CPU is too slow (waiting for CPU to do frame to frame calculations and issue draw calls)

 

[GreiverBlade]

my XFX R7950DD load at 99% constant when playing tomb raider (2013) in Ultimate settings, its nearly the 1st game to put my Gpu in that state

Crysis 3 in last settings does same but doesnt run smooth (obvious eh?) while Bioshock in latest settings does 70-80% (i never use Vsync im on a 75hz 1920x1200 screen)

 

[Aquinus]

Can anyone explain Gpu usage to me? When I play BF3, my CPU (i5 2500k) sits around 60-70% usage and GPU is at 99% usage, which is good. But now i'm playing F1-2012 and CPU usage is at 75-85% while GPU usage only at 65-75% usage. Why doesn't this game run at 99% usage? Isn't that ideal? Wouldn't I get more FPS out of the game if it ran at 99%? Another questions is why isn't running at 99%?

Not all games are multi-threaded so you're not always going to use all of your CPU resources, also if your CPU is sufficiently fast enough, your GPU becomes your bottleneck and vice versa. If both were at 100% that means that your computer has the absolute perfect balance of GPU to CPU power for that moment. Generally speaking you'll almost never see both fully loaded in a game.

 

[Kaynar]

In games like Dota 2 my 7970 doesn't go above 50% at 1900x1200 res. It all depends on games and (correct me if wrong) also if you are using Vsync.

If your CPU is a big bottleneck you might see your GPU being low on usage in some games where it shouldnt.

 

[anoobarak]

The OP's game settings might have VSYNC enabled, that would explain the intermediate usage of the card.

 

[GreiverBlade]

Not all games are multi-threaded so you're not always going to use all of your CPU resources, also if your CPU is sufficiently fast enough, your GPU becomes your bottleneck and vice versa. If both were at 100% that means that your computer has the absolute perfect balance of GPU to CPU power for that moment. Generally speaking you'll almost never see both fully loaded in a game.

so meaning running tomb raider at 95.4% cpu total (100/95.5/98.5/98.5) and 99% gpu is near the "perfect balance"? (ultimate settings 54fps average) although its not fully loaded but near

if so then i guess going back from a 2009 Phenom II X6 1035T 3.1ghz max to a 2008 Phenom II X4 955 BE 4.2ghz was a good idea (do Tomb Raider benefit more from a beefed up quadcore than a "average hexacore"?)