It's probably because of HyperTransport and floating point computation performance. I think HyperTransport made it easier for supercomputer vendors like cray to build better interconnects and traditionally opterons was a bit better at floating point ops. Also, opterons have 64Kb L1 caches where I think comparable Intel processors had 32Kb L1 caches. But this was all a couple of years ago ... the next generation of the fastest supercomputers will probably be Intel based.

I do not dispute the atrocities commited by the Japanese military during the war but that website is short on details and out right wrong in some cases. First of all the rape of Nanking is being taught in the history books... just a few of hundreds of history textbooks approved by the Ministry of education (or whatever it's called) did not explictly discuss the rape of Nanking, which by the way is something any "educated" japanese knows... now as far as the line "[Japan] Holds the second biggest defense budget in the world and bullies her neighbors in territorial disputes" this is just bullshit... first of all yes the Japanese spend lots on defense... but if you did a little checking... you will note that a significant chunk goes to paying for the American bases still in Japan... and as far as bullying our neighbor... that is pure crap... when did that happen... since the war only once has a Japanese ever fired on any non-Japanese... if you don't know what I'm talking about... a year or two ago the Japanese coast guard fired at a North Korean ship, which was caring illegal drugs, and they did only after being shot at with missles... and they still radioed in to get permission to fire a pea shooter at them...