System extremely slow under light load

[Bartosz Fabianowski]

> did you test the caches? I've seen such a behavior when cpu cache was
> disabled.

The Dell BIOS setup is very minimalistic and would not even allow me to 
turn off caches. So unless the FreeBSD boot loader somehow turned them 
off, the caches should be active. Is there some tool I can use to verify 
my caches are active?

> and it can be thermal throttle in case of bad contact between
> cpu and heatsink. try to reapply thermal compound

The CPU temperature is about 60°C-70°C when idle, 80°-90°C under light 
load and exceeds 90°C under heavy load. All of these readings are 
obtained from sysctl dev.cpu as ACPI always reports a temperature of 
0°C. If I fix the DSDT to correctly report temperatures, a medium to 
heavy load forces an emergency shutdown. To prevent this, I am running 
with the original broken DSDT and the CPU throttled from 1.8GHz to 
1.3GHz where it never exceeds 90°C.

Yes, the CPU is very warm. But it does not appear to be critically hot. 
The ACPI critical threshold is 95°C. It seems that this model (Dell 
Studio 15) always runs that hot. I have had several visits from a Dell 
technician who changed everything from heat pipe to complete 
motherboard. The temperatures never changed. Dell finally exchanged the 
entire laptop for a slightly newer model but the temperatures remained 
as they were. So reapplying thermal grease or even swapping components 
does not seem to change anything. Again, a tool would be useful that can 
tell me whether the CPU is throttling itself. Does such a thing exist?

- Bartosz