how can you know when the cpu is the bottleneck in games?

[WarWeeny]

i was wondering this, when the gpu lacks the horsepower it is quite clear to see/find out when, but on what things should i focus to see if my cpu may hold me back on games?

[Nyt]

"how can you know when the cpu is the bottleneck in games?"
The answer is quite simple, you check if your CPU says "AMD" :tongue:  

I think you can see a CPU bottleneck with your CPU usage is extremely high or maxed out most of the time in multi-threaded games

[WarWeeny]

"how can you know when the cpu is the bottleneck in games?"

The answer is quite simple, you check if your CPU says "AMD" :tongue:  

 

I think you can see a CPU bottleneck with your CPU usage is extremely high or maxed out most of the time in multi-threaded games

 

but ASSassins creed 3 had a cpu bottle neck in boston and my cpu wasnt maxed out then.

could change the graphics settings but the frames wouldnt increase so i asume that is a good example on how to spot a cpu bottleneck?

 

wonder how long it will take when games ask for 4ghz quadcore cpu's.... dont wanna part with my precious 760 yet :C

[EuroFight]

Some games, for example Planetside 2, provide a way to monitor which component is the bottleneck. In Planetside 2, if you press CTRL+F, it displays the current FPS, as well as the current bottleneck in the bottom left of the screen. 

[WarWeeny]

Some games, for example Planetside 2, provide a way to monitor which component is the bottleneck. In Planetside 2, if you press CTRL+F, it displays the current FPS, as well as the current bottleneck in the bottom left of the screen. 

 

hmm tempting to download planetside 2 >.<

but i doubt i have a bottleneck for that game tho

[EuroFight]

Some games, for example Planetside 2, provide a way to monitor which component is the bottleneck. In Planetside 2, if you press CTRL+F, it displays the current FPS, as well as the current bottleneck in the bottom left of the screen. 

 

hmm tempting to download planetside 2 >.<

but i doubt i have a bottleneck for that game tho

 

You're right, it's probably not worth downloading an entire game just to see what's stopping you from getting your 216th FPS... 

[wevsspot]

This is a tough question to answer because not all games are created equal when it comes to cpu versus gpu utilization.  As a general rule of thumb I'd propose that there are few games bottle necked by a multicore cpu running at 2.8Ghz or higher under normal circumstances.  Even the DirectX version being utilized can have an impact on cpu versus gpu "bottle necking".

 

For me the easiest way to determine whether a cpu is creating a bottleneck in a specific game is to snag some FPS data using FRAPs.  I begin the test with the cpu at stock clocks.  Record my data.  Bump cpu clock up by 20Mhz and re-run tests.  Leaving all other parameters the same except for cpu clock.  Compare results..............

[Puck]

**holy multipost, looks like it got Wevs too*

Edited March 5, 2013 by Puck

[WarWeeny]

**holy multipost, looks like it got Wevs too*

 

i missed it D:

 

@wev, 20mhz? i doubt you can see a difference xP

and what do you see as ''normal circumstances''?

Edited March 5, 2013 by WarWeeny

[wevsspot]

Run your own tests then.  Changes in cpu frequency (if cpu bound) from (for example 3.8Ghz to 4.0Ghz) will change the resulting FPS above the margin of error.

 

Normal circumstances = average number of services and/or other apps running in the background stealing cpu cycles

[RedFury77]

I think if you are running a game and not getting very high fps, then notice that your gpu usage is not maxing out, but cpu core usage is, then you are being bottlenecked by the cpu.  It can't feed the card\s fast enough to get better fps.

 

I was having this issue in BF3 in 64 player matches.  Compared to a 32/48 player match, my fps were noticeably lower.  IIRC, CPU was up at 90% or so while my cards were at 60%.  

 

On the otherhand, if your gpu usage is hitting the upper limits all the time you cpu is doing just fine.

[d6bmg]

The only way you can understand whether CPU is bottlenecking the game or not is by overclocking the CPU and comparing both the results.