How accurate are bottleneck calculators?

[Rothschild]

Hi all.

Was just wondering how accurate or reliable bottleneck calculators for CPU's etc at pc sites are?
For example here at pc-builds.com :: https://pc-builds.com/bottleneck-calculator/result/1c91ci/3/gpu-intense-tasks/1920x1080/

That link I've set it to 12900K paired with a 4090 at 1080p resolution as a quick example, says bottlenecked by CPU for GPU intense tasks by about 14%.

Thanks.

 

[Woomack]

It's not really accurate as every application uses different resources. It can be correct in suggesting that you need to pick a faster CPU or GPU, but the % is hard to consider accurate. Low graphics resolutions scale very high with CPUs, especially series like AMD's X3D. Still, one game needs more CPU and another more GPU performance. Some scale well with more CPU cores, but some still use mainly 2-4 cores.

The 12900K will bottleneck the 4090 at 1080p, but the 4090 is not considered a graphics card for low display resolutions, and it would be a waste of money.

 

[Rothschild]

Ok, would of been nice if it was like at least close to accurate. Yea I was just using 1080 as an example, thanks.

 

[Zerileous]

Agree with Woomack on all points. Run the same calculator at 4k or 8k and you'll get very different results. You gotta pick the right GPU for the task at hand first, then you can consider if the CPU is adequate. Probably no CPU on the market would satisfy the calculator for a 4090 at 1080p because that's not its intended purpose. Odds are if the CPU is relatively new, has 6-8 cores, it will be fine (at least for gaming in the 100-144hz range - some of the higher refresh monitors I'm not familiar with their needs).