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How to identify a CPU bottleneck?

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October 18, 2012 9:38:50 PM

I have just upgraded my graphics card and my power supply.
I have bought an ASUS GTX 670 replacing a GT240 so i can finally game on a PC
And have also changed my PSU to a Corsair AX750.

Now my processor is a Core 2 Quad Q8300 @2.99Ghz. Im unfortunately stuck on this OC because of my mobo.
My motherboard is an ASUS P5G41CM-LX. Im aware its the cheapo motherboards (i was not aware and greatly knowledged when i first built this system) and now im stuck on 399x7.5 to get a 2.99Ghz, if i go +1 on (ithink) FSB, it'll not boot and there's no way to change the Vcore too from the BIOS.

I'll be upgrading to new cpu+mobo in couple months time but in the mean time, how do i see/indentify a bottleneck?

Im looking to play games single and multiplayer like BF3, MoH:Warfighter, NFS:Most Wanted(2012), BO2

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October 18, 2012 9:42:26 PM

The only part that's bottlenecking your system is your CPU. To be honest, it is clocked a bit low, but it will be fine for a few months. Those games are demanding, but at 1080p, it's mostly the GPU doing the work.
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October 18, 2012 9:48:32 PM

Well i've got the games.
I was playing these earlier:
BF3 (just singleplayer), on Ultra settings 1080p and the CPU usage peaked at around 85%-90% while the GPU was maxed 98%-99%. Was getting 50-65fps, went 25 once when something blew up in front of me
Alan Wake too, CPU usage 40%-60% while the GPU was 80%-98%. Highest settings too and 1080p. Getting max 55-65fps

If i was to change the processors to like an i5 3670k and a P8Z77-V PRO mobo, will the CPU and GPU usage go down or..?

And i'd like to know, how do i exactly tell if there's a bottleneck? or i just have to guess?
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October 18, 2012 9:56:16 PM

There's nothing wrong with a GPU being maxed. But you don't want to CPU to max out. If you get he 3570K, CPU usage will go down. And there is a bottleneck. There's no way to "exactly tell". It's more like common sense. A Pentium III with a 680 is an obvious botteneck. You are using a a C2Q, which is a few years old with a few months old 670. While not extreme as the first example, your CPU will bottleneck.

Also, if you're getting the 3570K, I would not get the PRO mobo. Good mobo, but a cheaper one will perform just as well.
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October 18, 2012 10:05:17 PM

By changing CPU will i get an improvement in fps too?
How much performance in % do you think im losing due to my CPU?

About the mobo, what would you suggest?
If i was to get an i7 3770k, i heard it would help in like a BF3 multiplayer situation, true?
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October 18, 2012 10:08:45 PM

Yes, changing to a newer CPU will increase your FPS.
You're probably losing 15%. With a new CPU, your FPS will not drop to jump to 25FPS.
For mobo, I would get an ASRock Extreme 4.
The i7 would be better, but not by much, and it's $100 more expensive. Just get the i5.
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a c 94 à CPUs
October 18, 2012 10:21:02 PM

to find a bottleneck, lower the display resolution to 800x600 or lower, if FPS goes up significantly then there is not so much of a cpu bottleneck, but a gpu one.. If the FPS doesnt change much then the cpu is the bottleneck.
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October 18, 2012 10:27:56 PM

iam2thecrowe said:
to find a bottleneck, lower the display resolution to 800x600 or lower, if FPS goes up significantly then there is not so much of a cpu bottleneck, but a gpu one.. If the FPS doesnt change much then the cpu is the bottleneck.


This
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October 18, 2012 10:33:53 PM

obsama1 said:
Yes, changing to a newer CPU will increase your FPS.
You're probably losing 15%. With a new CPU, your FPS will not drop to jump to 25FPS.
For mobo, I would get an ASRock Extreme 4.
The i7 would be better, but not by much, and it's $100 more expensive. Just get the i5.

Is there a reason why you'd recommend Xtrm4 vs the other Z77s?
With the $/£100 saved, what would you say i should spend it on? Assuming ill have a 8GB ram, noctua hnd14(or whatever its called), samsung830, 1tb WDblack?

iam2thecrowe said:
to find a bottleneck, lower the display resolution to 800x600 or lower, if FPS goes up significantly then there is not so much of a cpu bottleneck, but a gpu one.. If the FPS doesnt change much then the cpu is the bottleneck.

Thanks! Ill try it out. Two questions, do i still do it on Ultra settings? And shall i just do in 1game(BF3) or more?
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October 18, 2012 10:34:12 PM

wrenaudrey said:
Well i've got the games.
I was playing these earlier:
BF3 (just singleplayer), on Ultra settings 1080p and the CPU usage peaked at around 85%-90% while the GPU was maxed 98%-99%. Was getting 50-65fps, went 25 once when something blew up in front of me
Alan Wake too, CPU usage 40%-60% while the GPU was 80%-98%. Highest settings too and 1080p. Getting max 55-65fps

If i was to change the processors to like an i5 3670k and a P8Z77-V PRO mobo, will the CPU and GPU usage go down or..?

And i'd like to know, how do i exactly tell if there's a bottleneck? or i just have to guess?


Battlefield 3 on Ultra is a beast for any system to run. I have an AMD FX8120 8 core clocked at 3.9 GHz and a 520GT GPU, and still only manage a smooth frame rate on High settings. Anyhow, if you ask anyone, hardly any difference between High on Ultra, at least in that game.
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