System extremely slow under light load

[John]

>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
>
>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 don't know which i7 you have, but the intel datasheet for the i7-870 states
that the maximum case temperature is 72.7C. The reported cpu temperatures will
be a little higher at this case temperature, maybe a few degrees. How much
higher I can't say without knowing the thermal resistance.

The i7-870 motherboard I have with a large cooler idles at about 40C. Under
heavy load it runs at about 65C.

John Theus