[NTLUG:Discuss] dmidecode... arghh!!

[Chris Cox]

On Thu, 2009-06-25 at 15:11 -0500, Chris Cox wrote:
> As a part of exploring your hardware, I mentioned dmidecode. Probably
> the best thing on an RHEL box... but it's just totally messed up with
> regards to CPU Max Speed and Current Speed ... neither are accurate or
> trustworthy.... sigh.
> 
> On newer boxes with a good sysfs/acpi implementation, try:
> /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq
> and the other values in that same dir for min_freq and cur_freq.
> 
> hwinfo --cpu seems to accurately handle the max_freq as Clock.
> 
> /proc/cpuinfo only reports the cur_freq.
> 
> I have NO idea where dmidecode gets its data.... it's just wrong.
> 
> So order of check:
> 
> /sys/... sysfs
> hwinfo
> dmidecode
> /proc/cpuinfo

Sadly, I was mistaken about hwinfo.  Does seem to be current speed and
can vary from processor to processor.

Rats....  if there's any good news, older sysfs (or no sysfs) tend to be
on older hardware which might not have variable frequency CPUs anyhow.