Server Clash: DELL's Quad Opteron DELL R815 vs HP's DL380 G7 and SGI's Altix UV10
 

Servers with the newest Intel six-core Xeon hit the market in April. The fastest six-cores Xeons were able to offer up to twice the performance of six-core Opteron “Istanbul”. The reason for this was that the age of the integer core in AMD's Opteron was starting to show. While the floating point part got a significant overhaul in 2007 with the AMD "Barcelona" quad-core chip, the integer part was a tuned version of the K8, launched back in 2003. This was partly compensated by large improvements in the multi-core performance scaling departement: HT-assist, faster CPU interconnects, larger L3 caches, and so on.

http://www.anandtech.com/show/3894/s...clash-dellr815