AMD Ryzen 9 3900X Linux CPU Frequency Scaling Governor Benchmarks

[Zan Lynx]

Did anyone encounter reboots during heavy load? My Ryzen 9 3900X / Asrock X570 Taichi (firmware 2.0) starts rebooting when CPU temperature reaches somewhere between 70°C and 80°C. For example when building Linux kernel.

RAM can certainly be an issue. I started out using 16 GB of HyperX 3600 on my 3900X. It worked pretty well. But after I installed the latest BIOS with AGESA ABB it started to fail with weird RAM errors during heavy compile workloads like Android AOSP image builds and big Rust compiles.

It didn't matter since the ECC RAM that I'd ordered arrived around then and I haven't had a single problem since. But it isn't running at 3600 either.

[TheYoshiGuy]

Did anyone encounter reboots during heavy load? My Ryzen 9 3900X / Asrock X570 Taichi (firmware 2.0) starts rebooting when CPU temperature reaches somewhere between 70°C and 80°C. For example when building Linux kernel.

I had the same thing happen literally yesterday. I was building yuzu-git-canary from the AUR (cpu at 100%) and the machine just reset part-way through.
I don't know what temp I was running, but I have water cooling.
Asus X470 Crosshair Hero VII (Wi-Fi) with a 3700X.

It's been stable playing DXVK games.

[rabcor]

Long story short: Always use performance.

[Raka555]

Long story short: Always use performance.

I like this idea, but will it have consequences for the longevity of the CPU ?

[Raka555]

I have a question about the core numbering.

In ryzenmaster you can see which is your best core and the runner up. Core 5 and 4 are the best and 2nd best on my 3700x
I can see in ryzen master that most tasks get schedules onto core 5 in windows.

Do the core numbers as reported by linux for example /proc/cpuinfo correlate to the core numbers as reported by ryzenmaster ?

Would core 5 of ryzenmaster correlate to cpu8 and cpu9 under linux ?

[Linuxxx]

Long story short: Always use performance.

Nope!
Schedutil is able to make smart decisions, like delegating a task to the CPU core with the least amount of wake-up time, for improved latency/smoothness/reaction times - something no other governor is able to achieve.

You know, there's a reason why Linux kernel developers want everyone to use only one scheduler; namely schedutil.

Android is again the one setting the pace here!
With a user-base in the billions, that shouldn't really surprise anyone...

Anyway, my prediction is that by 2021, we all will be using schedutil!
I really wonder what the opponents will be doing then...

[Shevchen]

Nope!
Schedutil is able to make smart decisions, like delegating a task to the CPU core with the least amount of wake-up time, for improved latency/smoothness/reaction times - something no other governor is able to achieve.

You know, there's a reason why Linux kernel developers want everyone to use only one scheduler; namely schedutil.

Android is again the one setting the pace here!
With a user-base in the billions, that shouldn't really surprise anyone...

Anyway, my prediction is that by 2021, we all will be using schedutil!
I really wonder what the opponents will be doing then...

As long as the Performance setting yields better results than Schedutil, this isn't going to fly. Esp. as Schedutil could take advantage of the better reaction time and even overthrow performance. But it doesn't.

[Raka555]

Did anyone encounter reboots during heavy load? My Ryzen 9 3900X / Asrock X570 Taichi (firmware 2.0) starts rebooting when CPU temperature reaches somewhere between 70°C and 80°C. For example when building Linux kernel.

I doubt it will be temperature that causes a reboot.
I will put my money on voltages dipping too low under load.
It might be the PSU or maybe the VRM on the motherboard.

[Raka555]

Nope!
Schedutil is able to make smart decisions, like delegating a task to the CPU core with the least amount of wake-up time, for improved latency/smoothness/reaction times - something no other governor is able to achieve.

You know, there's a reason why Linux kernel developers want everyone to use only one scheduler; namely schedutil.

Android is again the one setting the pace here!
With a user-base in the billions, that shouldn't really surprise anyone...

Anyway, my prediction is that by 2021, we all will be using schedutil!
I really wonder what the opponents will be doing then...

When all cores are busy 100% of the time, the scheduling strategy does not matter as long as you can keep the cores busy.

At less than 100% load it matters more to use the fastest cores, which means the scheduler needs low level knowledge of the hardware.

Also at light load it is better to stick to cores in the same compute complex to maximize cache hits etc. Again needing low level info.

It is not enough anymore to have a scheduler that does smart queuing based on load and idle states.

[Linuxxx]

When all cores are busy 100% of the time, the scheduling strategy does not matter as long as you can keep the cores busy.

At less than 100% load it matters more to use the fastest cores, which means the scheduler needs low level knowledge of the hardware.

Also at light load it is better to stick to cores in the same compute complex to maximize cache hits etc. Again needing low level info.

It is not enough anymore to have a scheduler that does smart queuing based on load and idle states.

Guess what - what you just described here is exactly what schedutil is positioned to do, while the performance governor is not!
(Or any other governor really...)

But hey, I guess you must know better than the Linux kernel wizards!