Summary: Two of these processors were purchased to speed up the workstation I use for editing video. Buying a new system wasn't feasible so quadrupling the processors on the one I currently use was the next option. Love every bit of my decision!
Summary: I had a HP xw9300 workstation, that came with one opteron 254 (2.8Ghz). The 2nd socket, and the 4 memory slots that went with that 2nd processor socket, were empty, many were delivered/ordered that way. I loooed up in HP's ssite, and they said, That to upgrade to the 285 Opteron dual core, I MUST use a HP blranded ER220A Opteron. I looked around, they were HIGH, around 400$.
Summary: This was a set of chips used in a VMWare ESXi 4.0 server. It was a completely compatible upgrade from a set of Opteron 265's. The speed is noticeably faster. Chips tend to run hot but is acceptable with a decent CPU fan and case fans. I'm very pleased with the performance of the CPUs and it was cheaper to upgrade to these procs versus building a completely new system to use newer procs.