Games are slower when using all threads

[opm0]

https://www.youtube.com/watch?v=QRfDgUNjpBk

Dolphin 5.0-9620

Backend: Vulkan (D3D11 and OpenGL are slower)
CPU: Intel Pentium Gold 4415U (2C/4T, 2.3 GHz, Kaby Lake)
GPU: Intel HD 610 (latest driver, 25.20.100.6519)
RAM: 8 GB DDR4-2133 (2x4 GB)

[DaRkL3AD3R]

You have discovered why it's better to get a non-hyperthreaded CPU than a hyperthreaded one for gaming. Those additional fake cores take away from the real ones if a program is not coded to fully utilize that many cores. Dolphin can only use 2 cores for rendering frames and thus by empowering the 2 real cores you have to fully work on rendering instead of trying to split it across 4 fake ones, you get better performance.



In most modern games this won't be a problem, it's rare but it still happens. Your best bet is to make a batch file to launch Dolphin with very specific affinity setup so you don't have to do it every time you go to play. Google search "batch affinity CPU" and follow instructions.

[DJBarry004]

Or just disable Hyper-Threading.

Note that the CPU is ultra-low voltage model, so don´t expect it to run at max clocks all the time during gameplay.

[opm0]

(02-26-2019, 01:18 AM)DJBarry004 Wrote: Or just disable Hyper-Threading.

Note that the CPU is ultra-low voltage model, so don´t expect it to run at max clocks all the time during gameplay.

The max/normal clock speed is 2.3 GHz (no turbo), and it doesn't throttle when running Prime95 (in-place large FFTs) + FurMark for 20 minutes (undervolted, CPU package power reaches 13.5W. Default PL1/PL2 power limits are 22W and 25W). 

The CPU affinity fix works fine, I prefer using that than disabling HT entirely in the BIOS.