GMP damages AMD Zen 5 CPUs

50 points by sjamaan


cajually

I’m not an ISA expert but MULX is a 32bit operand instruction afaik, which is very surprising to me that it is what it died on. When I read the title I was sure this was going to be about AVX512 power spikes.

I wonder if this just a microcode bug that is triggered by this tight loop mentioned, expected to never happen and not present in any test cases.

Will be very interesting to see where this goes.

wucke13

Time to short AMD stock? /s

I would really appreciate if this does not turn out to be such a disaster as with the 13th/14th gen Intel CPUs…

brucehoult

I note that they had FAR TOO MUCH thermal paste, and this is not good.

The paste is there to fill in micro-voids in the surface of the CPU and heatsink metal plates, as paste is a better thermal conductor than air. But the majority of the contact is supposed to be metal-to-metal, not the far less efficient metal-paste-metal.