To Hyperthread/Multithread or Not to...

codewizard1975

Question I have is: Is it beneficial to keep hyperthreading/multithreading support enabled or disabled? Given most CPU security attacks target it and that many games work better without it, what is everyone's thoughts on this?

I know from doing some testing on my Ryzen 9 5900x, I saw lower CPU temps with it disabled than when enabled. I didn't notice any difference in basic programs but more intensive ones like Handbrake and QEMU seemed to perform a little better.

Harvey

Do you want to have lower performance to eliminate a single attack vector while doing absolutely nothing to protect you from the majority of vulnerabilities in existence? No one can decide for you how paranoid you want to be.

The performance impact will be different application to application, you would have to benchmark it yourself in every single use case to help decide if its worth it to you and know that impact could change over time with updates. Some applications might even see improved performance with it disabled.

There is no way in hell I will ever consider disabling it on my personal system.

codewizard1975

I was curious if anyone had theirs disabled. I'm back to running it enabled right now after testing since I'm not doing anything that really benefits from running with or without it. The games I play don't act any different without it than with and am back to using my Intel Arc card for video encoding. The only virtual system I run is Windows 11 and that's about once a month or so for updating and a rare case I need to use the one Windows-based program that I still haven't found a perfect 100% linux-based version of yet.

As far as protecting against CPU attacks, I don't care about that. Don't visit any bad sites or run bad software that I shouldn't be running.

From my readings over the past couple of months, hyperthreading does come at a cost of an average of 30% performance on each core on the CPU since each core is jumping between 2 functions all the time. Some people have seen more but that all depends on the software your running.

I may go back to running non-hyperthreading in the future for when I need to do computational things like CPU based video encoding or graphics rendering.