I truly wish I had some older Xeon 5400-class hardware here to add to the mix. There’s a clear jump from the Xeon 5500s to the 5600s—and that’s just an evolutionary step up. Older Harpertown chips would have illustrated the gains inherent to Intel’s Nehalem architecture (and Gelsinger's claims) more poignantly.
Nevertheless, thanks to a new suite of benchmarks and a 5520-based platform that makes comparing LGA 1366-based processors relatively easy, we can clearly see where it makes sense to spring for a 24-thread, dual-socket workstation. Do a little research. Know if the software you’re running is threaded or not. If it is, a pair of Xeon X5680s, specifically, is very likely going to yield better performance than any other 2P configuration from Intel.
There are caveats, as we saw in Adobe’s CS4 suite. Divvying up 4 GB of system memory between 24 logical cores in a 32-bit application is asking for trouble, or at least a massive performance hit. So, make sure you’re running in a 64-bit environment if you want to come anywhere close to taking advantage of this platform’s potential in threaded software.
And just as we harp on the importance of building balanced desktops, the same holds true here. A potent dual-socket workstation should be complemented with plenty of memory and fast storage. In this case, 12 GB of DDR3-1333 and a pair of 160 GB SSDs in RAID 0 did the trick. Naturally, there are also gains to be had from a capable graphics card. And in some applications, your GPU will make all of the difference, while the Xeons have no impact whatsoever.
What we can say definitively is that the Xeon X5680—despite running 133 MHz faster than Intel’s older Xeon W5580—operates more efficiently than its predecessor in threaded software. It’s significantly more complex, what, with its two extra cores and 4 MB of extra L3 cache. But it fits within the same thermal envelope thanks to 32 nm manufacturing, and even manages to use less average power in our LightWave rendering test that the Xeon 5500-series chip.
And although a pair of hexa-core Xeons are much more power-hungry than a single Core i7-980X, the performance they enable gets threaded workloads done faster—fast enough, in fact, to yield a lower average watt-hour rating than the single-socket Core i7.
As for AMD, here’s hoping its SR56x0 and SP5100 chipset components pave the way for renewed competition in the workstation space. It’d be interesting to gauge the speed of the Opteron 6100-series’ 12 physical cores against Intel’s 6C/12T Xeon 5600-series, after all.