New motherboards often have a small fan covering one
of the bridge chips. Likewise, expensive graphics
cards have a fan on their processor. These fans
are cheaply made.

Is there protection for the MB/card to keep their
chips from frying if the tiny little fan fails?

On most motherboards built today, there's a temperature sensor
associated with the CPU (sometimes several e.g. individual temperature-
sensing diodes in the CPU's cores) and others on the board. The
sensor values can be read out (often via SMBUS) by the BIOS or other
software.

Better motherboards use three-wire fans with tachometers, where the
tach frequency can be read out of the sensor chip.

Modern BIOSes will usually let you set a temperature alarm, on a
per-sensor basis, and arrange for some sort of emergency action if the
temperature rises too high or the fan speed drops too low. The
actions can involve slowing the CPU clock to reduce power consumption,
sounding an audible alarm, triggering an OS shutdown, or (in extreme
cases) just halting the processor(s).

Graphics cards could implement similar fail-safe mechanisms. I don't
know if they do.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
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