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

[Mark Millard]

On 2021-Mar-18, at 13:01, Mark Millard <marklmi at yahoo.com> wrote:



> On 2021-Mar-18, at 12:05, Mark Millard <marklmi at yahoo.com> wrote:
> 
>> . . .
> 
> I've not done temperate testing in a
> while. One quick report I can make
> is that for my "always cpu_freq 2000
> always sdram_freq 3200" contexts
> with the RPI4B only doing whatever
> background tasks are involved in
> being basically idle but having
> the heatsinks and active cooling
> (fans):
> 
> # sysctl -a | grep temper
> hw.cpufreq.temperature: 35012
> dev.cpu.0.temperature: 35.0C
> 
> in a currently 15.5C or so ambient
> context is rather typical.
> 

So I started up a from-scratch "rebuild self"
-j buildworld buildkernel via an ssh over
Ethernet session. (This may minimize
interrupt overhead vs. the output text
scrolling the serial console?)

30+ minutes into the build:

I'm seeing figures like (the high so far):

hw.cpufreq.temperature: 49137
dev.cpu.0.temperature: 49.1C

(Such pairs give some idea of the
fairly short term variability.)

I'm only bothering to look once
a minute or so:

# while (true); do sleep 60 ; sysctl hw.cpufreq.temperature dev.cpu.0.temperature ; done

So far the widest fairly-short-term variation
was in:

hw.cpufreq.temperature: 45727
dev.cpu.0.temperature: 45.6C


FYI: The build reported:

make[1]: "/usr/fbsd/mm-src/Makefile.inc1" line 339: SYSTEM_COMPILER: Determined that CC=cc matches the source tree.  Not bootstrapping a cross-compiler.
make[1]: "/usr/fbsd/mm-src/Makefile.inc1" line 344: SYSTEM_LINKER: Determined that LD=ld matches the source tree.  Not bootstrapping a cross-linker.


Later I'll report the maximum(s) observed. But it will
be a few hours for the build to complete.

===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)