My friend Dan found this:
#include int
main(void) {
while (1)
memset(a, 0, 4*1024*1024);
return 0;
}
We can reliably lock up the AMD64 systems available to us running this code. We've tried on a 3500*, 4000*, and 4400+. We've tried with 64-bit Linux and 32-bit Windows. The only other common thing is that these are nForce4 chipsets, but that shouldn't matter... Lockup isn't instant, but it's fast; a couple of minutes.