PC Processors

[qswan]

AMD Ryzen 5 3400G (CPU) with an MSI x470 (MoBo), 16GB RAM, a Radeon 5600XT (GPU), and SSD.

I have an issue where my games have "FPS stuttering".  This is where the FPS drops to 35-50 FPS from 150 FPS several times each second.  The result is choppy gameplay based on inconsistent frames.

I noticed that Core0 is at max utilization while the other 7 hover around 24-30%.  Disabling Core0 for the particular game solves the problem.  The FPS is consistent and hovers around 300 FPS.  Core0 drops to about 67% utilization while the other 7 cores increase to 30-40%.  I have to use this fix everytime I launch any game.

Why is this happening, and is there an optimization that does this?

[pokester]

You might want to talk to AMD support about this. You may have a faulty APU. 

https://www.amd.com/en/support/contact-email-form 

[Thanny]

Could be some installed software.  You should try monitoring CPU performance across running programs when this happens, to see if something is periodically hammering the CPU.  Especially something low-level, like anti-virus, as some things in Windows only work on core 0.