RPI4 clock speeds and serial port ( temperatures idle and -j4 buildworld buildkernel )

[bob prohaska]

On Sat, Mar 20, 2021 at 03:44:06AM +0100, Klaus K??chemann wrote:
> 
> as Mark said, powerd isn???t enabled by default in releases , so the freq is @600 by default.

At the time I'm thinking about it would have been -current, most likely. I
knew of powerd's existence, but never thought to use it until you bought
the idea up.


> So 17 hours @4x600 .
> with powerd enabled you should have automatically exactly 4x1500 during the complete compilation time.

The most recent test on the 8GB Pi4 finished in 9 hours. That was after
running make cleandir twice, but having the installed system and the
sources relatively close (days) in age, on -current. That's with powerd
enabled, but no other speedup tweaks. Temps were just under  60 C, with
a fan in the case but no heatsinks on the ICs. 


> sysctl dev.cpu.0.freq will definitely show the current freq.

On a Pi3 with GENERIC-MMCCAM kernel  (also running buildworld) it reports
bob at www:/usr/freebsd-src % sysctl dev.cpu.0.freq
dev.cpu.0.freq: 1200
also with no other speedup efforts beyond powerd. That machine has heastinks
on the ICs but only a fan blowing in through the openings in the plastic case.
It's around 60C. 

So far the effects of powerd seems to be uniformly good, with 
no downsides. Next, to try a Pi2 v1.1 (armv7)

Thanks for mentioning powerd, it never crossed my mind.

bob prohaska