Hey Guys,
Just created an account to thank you for putting all the info together here. So while I am writing this from Fedora,I am listening my playlist from Windows machine. My specs:
Hardest part was splitting host and guest nvme, they had same id. Only issue I have now I can not set cpu model as host-passthrough, windows shows kernel panic, so I am on opteron g3, not even sure if it will make difference.
I am using java fix but in last 2 VM start I forget it running java app, didnt have any issue.
Thanks again & have nice day&afternoon or whatever timezone u are
Burak
The latest QEMU supports epyc as the cpu model. I suggest trying that.
The difference is that QEMU might not tell the OS that it supports all the fancy new CPU features (which I don’t know enough about) and may need to translate some instructions. It’s not a serious problem unless you’re doing stuff where latency is important.
Not to threadjack but I have found that very recently on new kernels and versions of cpufreq that they can mess with or undo overclocks somehow. I thought my tr system was feeling sluggish under load, and sure enough it was backing off to basically stock even though I’d overclocked it to 4.1ghz.
To fix I had to disable my pstate/cstate oc and go back to fixed voltage and multiplier. Extra heat and electromigration I guess. Will deal with it later.
Thanks I will definitely give a shot, at least I will compare g3 vs g5 vs host, what especially I wonder is hyperthreading behaviour.
First of all I am a newbie overclocker! Only thing I had similar experience with: perf dmesg messages (perf interrupt took too long) . When I had this messages, I assume I have bad V setup or memory. After increasing V they are gone. And I hope when lscpu says its 4 ghz it is 4:) I also use fixed V and Multiplier. Only addition on bios I have disabled below options:
Overlocking enhancement
Core Performance Boost
EPU power saving
increased temp a bit but when I run this machine I game or use some VM, so I dont need powersave.
On OS I run cpupower with performance governor, when I stress tested I disabled perf to catch throttling:
echo 0 > /proc/sys/kernel/perf_cpu_time_max_percent
Yet still I am looking reliable bencmarking ways, couldnt find good linux benchmarking article/material or I am lazy enough, atm just using mprime and my own script.
I had this issue also and added that line but as I was mentioning to @SgtAwesomesauce before, using Opteron_G2 seemed to fix things (epyc didn’t seem to work for me but I’d need to test it again) instead of copying host cpu configuration as well. A lot of guides out there say to copy host configuration, probably an issue on zen though.
I’ve been failing, on and off, to get PCI passthrough working with Fedora on my Prime X399-A motherboard since the end of 2017. Please point me to the instructions that you used. Which version of the BIOS are you running? Sorry for the necro.
