REMEMBER OUR dual-CPU Xeon W5590 review? Well, here's its single-socket cousin, the workstation oriented Xeon W3580. No, it doesn't run at 3.2GHz like the Xeon W5580, but at 3.33GHz like the W5590, so don't get confused by the numbering. It is fully plug-compatible with the desktop Core i7 parts, and you can consider it a workstation twin of the Core i7 975XE, with added ECC memory support.
I found the ideal matching mobo for it. The Asus P6T7 WS Personal SuperComputer, based on the usual X58 chipset, supports 24GB RAM, on-board SAS, 16+2 phase claimed power stage, and... seven (7) PCIe X16 physical slots! You can run them either as four full X16 slots, seven X8 slots, or anything in between. So, you can have a full TriSLI with full bandwidth for each card, plus two spare X8 slots for extra RAID controllers or other I/O. Or, you could have four dual-GPU cards in there for some serious GPU supercomputing. That's done by adding two Nforce 200 bridge chips to double the total PCIe lane number, of course.
I put together the system with a pair of Asus's brand new Matrix GTX285 cards in SLI, as well as a CoolerMaster V8 high-end heat sink, the trusty Corsair HX1000 PSU and 6GB of Gskill DDR3-1600 low latency CL6 memory.
Now, the P6T7 WS is no ROG extreme mobo, but it was designed with a decent amount of overclocking in mind for a typical engineering or multimedia workstation user, at the time when one may really need it, those tight deadlines for the render or compute analysis to finish faster. This being a Xeon CPU, I had no hope for overclocking, as with locked multipliers we'd have to go for painful Base CLK changes instead of simple multiplier upping.
Just out of curiosity, I put the multiplier BIOS setting from default up to 30, not expecting it to work as Xeons are usually locked, and restarted the system. Voila! It ran at 4 GHz without problems, and even booted Windows. It also handled the DDR3-1600 and 1866 settings fine. So, it seems, the Xeon W3580 - at least the one I have - is unlocked and free to go up sky high into the gigahertz heavens. Keep in mind, this is the same D stepping as the Core i7 975XE, plus these are workstation/server grade CPUs meant to last. So, this baby should last long and high, and the P6T7 WS handled the 4GHz setting flawlessly in both auto and manual reduced-voltage 1.35v CPU Vcc modes. The usual Windows Sandra benchmarks had exactly the same results as the i7 975XE, but we'll be trying the SLI with the Matrix cards in the follow up.
Now, does it mean that the otherwise identical dual-CPU Xeon W5590 that we tested earlier is also multiplier unlocked? Well, no reason to doubt it, the only problem being that the current i5520 chipset dual-CPU mainboards don't have a BIOS option to change the multiplier ratio. Well, dear SuperMicro, Tyan, Asus, Gigabyte et al, how about adding that option and, why not, beefing up the CPU power feed a bit? Then, each and every one of your workstation boards could be a worthy successor to the Intel Skulltrail. Can't complain about having dual 4GHz quad-core CPUs fed by six DDR3 memory channels. µ
Performance, overclocking, multi-GPU expandability.
You'll have to pay for it, count on 2,000 quid for the combo sans the GPUs.
Geez, Intel, why not just call it W3590 and spare laymen the confusion?