snip

Unlike the CPU chip-temp monitoring on modern motherboards, most
video cards have no GPU chip- temperature monitors, although the
design and thermal-stress rules are exactly the same as for CPUs. The
latest video cards ATi9700, 9800, FX5800, FX5900 cost more than most
CPUs and disspate as much power as a 2.6GHz P4. Out of these only
the FX5900 has built-in user-accessible chip-temperature monitoring.

Seems to me the FX5900 needs it! The FX chips are the AMD T-Birds of the
GPU industry!