Re: PC speaker
From: Kyle Moffett
Date: Thu Jun 14 2007 - 20:37:09 EST
On Jun 13, 2007, at 15:53:30, Pavel Machek wrote:
Other great examples are hardware that allows you to control
voltages, fan speeds, and operating frequencies. Sometimes you can
overvoltage it directly and blow it immediately. Other times, you
can increase the voltage and operating frequency and decrease the
fan speed to the point where it stops spinning. This is possible
on many modern graphics cards and CPUs.
Not true for cpus; try it before spreading FUD. Thermal protection
will kill the machine when cpu goes over 95C or so.
Well, sorta. Things tend to die early heat deaths if you repeatedly
spike the temperature (different rates of thermal expansion and all
that jazz). If you alternated repeatedly between max-CPU/no-fan and
no-CPU/max-fan, staying just within the thermal kill limits and
spending 3/4 of the time at near max temp, you'd probably have a 30%
chance to kill an average CPU within a couple weeks.
I know when designing the G5 CPU, IBM had to be _really_ careful
about the variably high operating temperature. Their first few
designs ended up having BGA breakdown well before the desired
lifetime due to thermal creep (long-duration at high temp) and
fatigue shear failure (alternation between high and low temp).
There's a paper somewhere on the web about the whole deal.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/