How To Tell If My CPU Is a Bottleneck?

[Faceman]

Not running a 4K I dont

I'm sorry, a lot of us missed that you are playing at Ultra 4k. You shouldn't be getting any CPU bottlenecking because you are almost entirely GPU bound. Now, some games are going to have higher minimums with a stronger processor, but overall you should have seen an increase spin performance.

By chance, is your monitor only 30Hz? Or is it 60?

[D2ultima]

Run HWMonitor, HWinfo64 or MSI Afterburner. Monitor your GPU Load % vs your CPU Load %. If your CPU is sitting pinned at 100% and your GPU is below 95-99% then you're bottlenecked.

A CPU at 100% load is almost impossible. Also, Windows 8's task manager showing "100%" only means "80%" or so (at least with i7s and hyperthreads).

 

One way to tell if a CPU is bottlenecking your GPU is if your GPU doesn't consistently hit full load with V-Sync off.

No, there are games that won't max CPU *OR* GPU because badly coded.

See: anything made by Bohemia Interactive

 

I'm sorry, a lot of us missed that you are playing at Ultra 4k. You shouldn't be getting any CPU bottlenecking because you are almost entirely GPU bound.

Actually... while 4K does put massive load on the GPUs rather than the CPUs, it doesn't mean that it is impossible to max a CPU at 4K. ESPECIALLY in very CPU-heavy games like Dying Light or GTA V. Also, if he has multisample-type AA off, that's another huge free load; enough so to add 20+fps in some games.

 

Not only that, but some games are single-thread heavy. Like Killing Floor 2. I go WAY below 60fps even at 1080p because sometimes with all the action my core #1 hits about 95% and the load isn't properly split across cores. Final Fantasy 13 is another example of a game that was basically designed for a single core GPU. Unity engine games also devour single CPU cores for breakfast, lunch and dinner.

 

Basically @HectiKCookiE , the only way to tell is by looking at your CPU and GPU utilization in real-time. If you notice your CPU has a huge load on it and your GPUs are not loaded at all (like I get in GTA V, where my GPUs go down to ~50% and my i7 is running at 80%) OR if you notice one core is far more heavily loaded than the others, near maximum load, and your GPUs are not loaded much at all (FF XIII and Terraria are good examples of games where this can easily happen), then you're at a CPU bottleneck.

 

And I don't give two meowmixes what anybody says. CPU bottlenecking happens a LOT and people don't even realize. Some games are designed for a dual core and will split their load across say... four cores, and your four cores will never pass 50% load each. Other games are designed for a quadcore and will split the load across hyperthreads or (in your case) your 8 cores, and you will notice your CPU util never gets anywhere NEAR 100%, but your GPUs will not work well. That's a bottleneck. In the hyperthread scenario, if you see a game (let's take Battlefield 4 for example) using ~75% of an i7, it's because on an i5 that'd be 100% load, and it isn't capable of using the hyperthreads to squeeze out much more performance, but the fact that the hyperthreads exist and are able to split the load means your CPU has "leftover power" you can make use of (namely with other programs). In your scenario, it probably just automatically splits the load across all the cores, but the game isn't coded to use more than X number of CPUs, so when it hits the max load of x number of cores, it stops using the processor.

 

Higher resolutions can "force" a GPU bottleneck... sure. But it won't make the game use "less" CPU power. What happens is that it switches the bottleneck's position.

Let's say with infinite GPU power your CPU at 4K can attain 48fps in a game.

Let's say your R9 290X can attain 41fps in that game.

Let's say with infinite CPU power, your second R9 290X can attain 78fps in that game.

Tossing in your second R9 290X here will switch your bottleneck from 41fps to 78fps on the GPU side, and allow the CPU bottleneck of 48fps to become the new limiting factor.

Let's say tossing in an i7-5930K @ 4GHz raises your CPU limitation to 100fps. Then you're now GPU limited.

Let's say tossing in a third R9 290X raises your GPU bottleneck to 110fps. You automatically become CPU limited again, to 100fps.

 

On the other side, at 1080p, your CPU is a bit more free. Let's say the 5930K's bottleneck is 130fps at 1080p.

Your GPUs, rendering 1/4 the work, now has a limiting factor somewhere around 300fps. Here is where users would say "three R9 290X's are overkill". 

[Godlygamer23]

A CPU at 100% load is almost impossible. Also, Windows 8's task manager showing "100%" only means "80%" or so (at least with i7s and hyperthreads).

 

No, there are games that won't max CPU *OR* GPU because badly coded.

CPU at 100% load is almost impossible? What are you talking about? I've fully loaded my CPU doing tasks like folding@home(on 660 Ti) while watching Youtube videos and playing games like Skyrim.(things would stutter)

 

Most modern titles will allow the GPU to be pushed to 100%. In regards to CPU usage, that is still a CPU bottleneck - whether it's caused by the game using only one core, or the CPU just being weak, the CPU is still somewhat to be blamed. If you upgraded a CPU to one with stronger single threaded performance, performance will improve in that game. The bottleneck lessens - I get that the root cause in that scenario is the game or the engine though.

[D2ultima]

CPU at 100% load is almost impossible? What are you talking about? I've fully loaded my CPU doing tasks like folding@home(on 660 Ti) while watching Youtube videos and playing games like Skyrim.(things would stutter)

I meant in gaming only, sorry.

 

If you're doing other things it's easy to hit 100%. I'm not that silly.

[Blackie Sheen]

One way to check if your cpu is a bottleneck is to keep logs of gpu usage using something like GPU-Z when gaming. If the gpu usage drops under 95%, you have a bottlneck on your hands.

But, regarding your cpu specifically, it definitely is a bottleneck and would still be when overclocked although it would be less significant

[D2ultima]

If the gpu usage drops under 95%, you have a bottlneck on your hands.

Uhh... no. It doesn't mean there is a direct bottleneck that can be fixed by getting a faster processor or something. Everything made by Bohemia Interactive is blatant proof of this. You distinctly need to check the balance between the CPU and the GPU to see where the bottleneck lies. And hell, if you don't have oodles of excess RAM, check that too.

[Blackie Sheen]

Uhh... no. It doesn't mean there is a direct bottleneck that can be fixed by getting a faster processor or something. Everything made by Bohemia Interactive is blatant proof of this. You distinctly need to check the balance between the CPU and the GPU to see where the bottleneck lies. And hell, if you don't have oodles of excess RAM, check that too.

Oh please. Excess ram. You must be running a lot of shit in the background, at least in most game before getting excess usage of ram if you have 8 Gb of ram in the system.

 

Plus, arent games by Bohemia Interactive very poorly optimized? If it is, then your argument is invalid since its only targeting a single game company producing poorly optimized games.

 

On top of that, the thing I said is a general advce and should not be considered as a universal law of bottleneck verification

[D2ultima]

Oh please. Excess ram. You must be running a lot of shit in the background, at least in most game before getting excess usage of ram if you have 8 Gb of ram in the system.

 

Plus, arent games by Bohemia Interactive very poorly optimized? If it is, then your argument is invalid since its only targeting a single game company producing poorly optimized games.

 

On top of that, the thing I said is a general advce and should not be considered as a universal law of bottleneck verification

Yeah... and there's people who are on 4GB or 6GB. I didn't specify how much RAM, I simply said "unless you have oodles of excess RAM". 8GB isn't enough for me, for example.

 

Yeah, they are. That's the point. You will see well under 95% util and WELL under even 50% CPU util in their games and it'll still give you crap fps.

 

A general "if you're not at 95% or above GPU util you're being bottlenecked" is a statement with too many flaws to make sense. Especially where multi-adapter configurations are a thing.

[HectiKCookiE]

I'm sorry, a lot of us missed that you are playing at Ultra 4k. You shouldn't be getting any CPU bottlenecking because you are almost entirely GPU bound. Now, some games are going to have higher minimums with a stronger processor, but overall you should have seen an increase spin performance.

By chance, is your monitor only 30Hz? Or is it 60?

60hz thought dp 1.2 I wouldn't go near a 30hz panel.

[Luckylock]

Oh please. Excess ram. You must be running a lot of shit in the background, at least in most game before getting excess usage of ram if you have 8 Gb of ram in the system.

 

Plus, arent games by Bohemia Interactive very poorly optimized? If it is, then your argument is invalid since its only targeting a single game company producing poorly optimized games.

 

On top of that, the thing I said is a general advce and should not be considered as a universal law of bottleneck verification

 

It seems a lot of games are like this:

i7-4790k @ 4.6 GHz

GTX 970

 

Borderlands 2:

 

Planetside 2:

 

GTA V is also CPU bottlenecked when trying to run at 80+ FPS.

 

The list goes on, notice the CPU utilisation on a single core never goes to 100%. I've only had that in Far Cry 4 and my GPU was the bottleneck anyway.

 

On topic: Your CPU most of the time is the bottleneck when your GPU utilisation is not near 100%.

[Blackie Sheen]

-snip-

Sorry. I just noticed that I havent mentionned that this trick is only insightful if the cores involved in processing for the game are fully utilised. Hope that clears up what I meant. Those gpu utilisation look very weird also. Like WTF. The thing I said should generally be right but those gpu utilisation are just stupid. Are these games frame-capped?

[Luckylock]

Sorry. I just noticed that I havent mentionned that this trick is only insightful if the cores involved in processing for the game are fully utilised. Hope that clears up what I meant. Those gpu utilisation look very weird also. Like WTF. The thing I said should generally be right but those gpu utilisation are just stupid. Are these games frame-capped?

 

The frames aren't being capped and the temperatures are good.

 

I am running on lowest graphical settings to get the smoothest experience, that would explain low GPU usage and the CPU bottleneck.

 

Anyway, my point was that CPU cores don't hit 100% when the CPU is the bottleneck in games. It's just weird to me that the games aren't using the full potential of a CPU core.

 

Even the i7-4790k overclocked is holding back the 970 in a lot of games if you want to achieve 144+ FPS. >_<