The 50x statement looks out of context. Probably the required algorithms benefit from a huge data bus, the special fast XDR RAM, or having processing cores very close.

Might not be that much of an exaggeration, though. The AF probably uses it to simulate things like airframes and nuclear explosions; those are embarrassingly parallel, so you'll get full use of all the cores. At 8 cores per box [1], that gets you up to 14k times faster, if the cores are the same speed as that laptop.

[1] The Cell has one PowerPC core and 8 SPUs; but the PS3 is shipped with one SPU disabled, so they can get the yield up.