hi,
well, again this is not surprising at all, lets take a closer look at CPU specs:
AMD II X2 550, 3.1Ghz, L2-Cache: 2x 512kB, L3-Cache: 6MB shared
Intel Xeon 3110, 3.0Ghz, L2 Cache 2x 3MB
for heavy multithreading, like maxxpi do, a large *shared cache
where every core can access...