Alpha a power hog, surely you jest...

Nor was the Alpha the only 64 bit Linux game in town as of late 1999. AFAICT R4K support was rolled into the kernel around mid 1999 - although I'm pretty sure it was available outside of the mainstream Linux kernels before that...

For the EV6 you might have a point... P3 Katmai core came out in 1999, at that stage the most power hungry Alpha was the EV6 and it ate 73W@600MHZ in 1999. Meanwhile the Katmai had a "TDP" of ~43W@600MHz, that said Intel's TDP figures are usually quite a bit smaller than the peak figures quoted by the rest of the industry at the time, so in reality the gap would have been a significantly smaller.

Meanwhile the 1999 vintage EV5s were eating ~25W@666MHz, so the Katmai AND the EV6 look like the power hogs to me. ;)