Back in December 2009, I reviewed three of the newest Intel Nehalem Xeon-based servers from Dell, Fujitsu, and HP and found that the Xeon X5500-series CPU provided substantial performance gains over all other server CPUs on the market. The Xeon's new architecture, QuickPath Interconnect, and on-die memory controller put the Nehalem at the top of the server food chain.
A year later I find myself staring at a Dell PowerEdge R715 chassis outfitted with a pair of the latest and greatest AMD Magny-Cours Opteron processors, and I wonder if the Opteron's performance can take the top spot away from Intel. My 2U rack-mount chassis is a work of engineering art, and it's not just because of the dual Opteron 6174s stuffed in the box. From the excellent performance to the large amount of system RAM to the densely packed storage using 2.5-inch drives, the R715 is a great platform to build any data center around.
Magny-Cours: Not your papa's Opteron
The heart of the Dell PowerEdge R715 is the new Opteron 6000-series CPU, which is a major departure from previous Opteron processors. The 6000 series comes with either 8 or 12 physical cores on the die, 128K L1 and 512K L2 cache per core, and 12MB of shared L3 cache. Clock speeds range from 1.8GHz to 2.3GHz. (For comparison, the latest Intel Xeon 5600-series processors have up to 6 physical cores, or 12 threads with Hyper-Threading enabled, also with 12MB L3 cache and clock speeds up to 3.33GHz.) In addition to the two 12-core 2.2GHz Opteron 6174s, my test system included 32GB of DDR3 RAM, three 146GB 15,000 RPM SAS hard drives, dual hot-swap power supplies, and a four-port copper Gigabit Ethernet adapter. The new Opteron requires a much larger socket, the LGA1944, instead of the smaller LGA1207 Socket F.
Other improvements are HyperTransport 3 (HT3), support for 1,333MHz of DDR3 RAM, quad-channel memory, and AMD-V (AMD Virtualization). HT3 is the communication path between processors and I/O, much like Intel's QuickPath Interconnect. HT3 ups the interconnect rate from HyperTransport 2's 2.8GT/s to 6.4GT/s (that's gigatransfers per second) -- also the speed found in Intel's QuickPath.