System extremely slow under light load

[Ian Smith]

On Mon, 25 Apr 2011, Bartosz Fabianowski wrote:
[..]
 > See above: Unfortunately, the machine did nor respond well at all. Instead,
 > it is overheating even worse.

Sorry to hear none of that helped.  It seems a very serious problem, and 
it would be useful to know if it behaves any better under linux or not.

 > > Try using C2.  It helps more with some CPUs than others, but it's worth
 > > a try for further reducing heat, especially at idle.  Ie in rc.conf:
 > > 
 > > performance_cx_lowest="C2"
 > > economy_cx_lowest="C2"
 > 
 > I have set dev.cpu.X.cx_lowest="C2" at run-time. If I understand correctly,
 > this should achieve the same effect. The CPU does not seem to ever make it to
 > C2 though, even after I enable it:
 > 
 > %sysctl dev.cpu | grep cx_usage
 > dev.cpu.0.cx_usage: 100.00% 0.00% last 270us
 > dev.cpu.1.cx_usage: 100.00% 0.00% last 399us
 > dev.cpu.2.cx_usage: 100.00% 0.00% last 403us
 > dev.cpu.3.cx_usage: 100.00% 0.00% last 404us
 > dev.cpu.4.cx_usage: 100.00% 0.00% last 323us
 > dev.cpu.5.cx_usage: 100.00% 0.00% last 313us
 > dev.cpu.6.cx_usage: 100.00% 0.00% last 174us
 > dev.cpu.7.cx_usage: 100.00% 0.00% last 137us

You need sysctl hw.acpi.cpu.cx_lowest="C2" instead .. that's what 
/etc/rc.d/power_profile adjusts when you apply or remove power.
I doubt it's likely to help much given the scale of overheating.

 > >   >  dev.est.0.freq_settings: 1734/45000 1733/45000 1599/41741 1466/38582
 > >   >  1333/35485 1199/32426 1066/29457 933/26552
 > > 
 > > With throttling disabled, those are what you should be left with for
 > > dev.cpu.0.freq_levels.
 > 
 > Yes, these are the frequencies I have available now. 1333 makes the machine
 > idle around 85°C, 1999 leads to 78-80°C.

That's pretty sad.  Not sure what the first two differing by only 1MHz 
means .. but I'm out of ideas, and my depth.

cheers, Ian