Re: [LAU] System Configuration: kernel, CPU frequency, hardware timers

On Tue, 28 Aug 2018, Ralf Mardorf wrote: Not any more. It is there until 16.04 at least but vanishes at least by 18.04 to be replaced by /lib/systemd/system/ondemand.service which calls /lib/systemd/set-cpufreq. The name ondemand is, as you say, misleading and powersave even more so. where powersave used to be "run at lowest speed" it is now what ondemand was supposed to be, but handled by the cpu itself. ondemand, I have read, uses more power than performance, but powersave works correctly. my cpu temp is higher at idle in performance than powersave... I don't have anything old enough to test ondemand with. In anycase, ondemand.service sets powersave in my case. Installing cpufrequtils and setting it to set performance at boot no longer works as I said due to kernel modules missing at the time it runs at boot. Using a utility to change cpu govering on the fly according to use does make sense. For many people using usb devices at 128/2 or higher, this probably doesn't matter, but I like to make things work as well as possible at 16/2 so that at higher latency I don;t get surprised... but most usb devices don't work that low. (USB clock is 1ms so probably 32/2 is lowest). USB is not a gift for low latency audio, but a great boon for Linix compatablility. -- Len Ovens www.ovenwerks.net