Digit-Life has taken a look at the performance of a server with four dual-core Opteron 875 processors:
"In our previous reviews we examined various multi-processor and/or
multi-core AMD Opteron configurations many times (you can learn the
results of these tests in the following articles: SPEC CPU2000. Part
12.1. AMD Opteron: Integrated Memory Controller and Dual-Processor
Configurations and SPEC CPU2000. Part 21. AMD Opteron: Dual-processor
and "Dual-processor - Dual-core" Systems). In this article we again
return to these platforms, represented this time by the STSS QDD4400
server, based on four dual-core AMD Opteron 875 processors.."