System extremely slow under light load

Bartosz Fabianowski freebsd at
Mon Apr 25 14:04:37 UTC 2011

> 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.

I am still on the hunt for a bootable Linux distribution. I am in the 
unfortunate situation of having no CD-Rs at hand. And because it is 
Easter, shops are closed.

Most Linux distributions require you to run a proprietary tool from 
inside Windows or another Linux installation to create a bootable USB 
medium. I found a USB image for OpenSUSE but that failed to boot. I am 
continuing to hunt...

> 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.

I use the correct sysctl now, the cx_lowest value changed from C1 to C2 
for all CPUs but nothing seems to have changed otherwise:

%sysctl dev.cpu | grep cx_usage
dev.cpu.0.cx_usage: 100.00% 0.00% last 230us
dev.cpu.1.cx_usage: 100.00% 0.00% last 216us
dev.cpu.2.cx_usage: 100.00% 0.00% last 159us
dev.cpu.3.cx_usage: 100.00% 0.00% last 323us
dev.cpu.4.cx_usage: 100.00% 0.00% last 320us
dev.cpu.5.cx_usage: 100.00% 0.00% last 357us
dev.cpu.6.cx_usage: 100.00% 0.00% last 378us
dev.cpu.7.cx_usage: 100.00% 0.00% last 374us

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

Thanks for all the tips. I will report back once I have had a chance to 
compare with Linux. If nothing else helps, I will call Dell again in the 
futile attempt to have them magically fix the issue somehow.

- Bartosz

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