AMD Opteron 6100 review

For the first time in what seems like years, AMD has managed well and truly to trump Intel on fundamental specification of a new processor. The Opteron 6100 workstation and server processor range, codenamed Magny-Cours, launches today. Sporting eight or 12 cores per processor, it outstrips the newest Westmere-series Intel Xeon 5600 parts with their maximum of six cores.

It’s not a case of being in the lead for a token five minutes, either. Intel’s ‘Nehalem EX’ Xeon 7500 server and workstation parts – due any day now - will still only have a maximum of eight cores, so AMD will retain the lead in this area for a while yet.

We recently had a chance to test one of the first ever fully working 6100-series 12-core machines - a 1U rack system from Boston Limited fitted with two of the new CPUs. We were also able to run a limited set of CPU-intensive benchmarks to get an idea of the raw performance of a 24-core, 2P system.

The new platform

The 6100-series processors need to be fitted to a new 6000-series platform. That’s because AMD has abandoned Socket F for an all-new Socket G34, so moving to Magny-Cours will mean a wholesale upgrade.

Mitigating this is the fact that the 6100 series removes an artificial cost barrier that the previous tiered 1000, 2000 and 8000 Opteron line-up imposed. Previously a 4P system required an expensive 8000-series processor to work, and a 2P required at least a 2000-series. The 6100 series removes that artificial barrier – they’ll work in 1P, 2P and 4P machines, for a clear upgrade path as long as you think about your requirements ahead of time and buy a suitable chassis.

Features

Intel still has the edge on fab technology. The new processors are based on a 45nm fabrication process where the 5600 and upcoming 7500 Xeons are 32nm parts. That may explain the clock-frequency disadvantage in comparison to Intel: the top end 12-core Opteron, the Opteron 6176SE, runs at 2.3GHz.

That’s in comparison to a base frequency of 3.33GHz, and Turbo frequency of up to 3.6GHz, in the highest-end six-core X5680 Xeon. Cramming all those cores in also needs an unusually large, rectangular processor package, hence that new Socket G34.

Level 3 cache, shared between all cores, has been doubled to 12MB, matching Intel, with the per-core Level 2 remaining at 512KB.