Intel has offered Hyperthreading, a hardware level multi-thread optimization technique that turns a single physical core into two “virtual” cores, in their last several processors.  In my experience, its use in CPU-heavy applications (like Rendering) hasn’t been worth the penalty, typically increasing render times as you watch CPU’s trade off performance.  As one virtual core works, you see the other virtual core drop to 60-70% utilization.  The new Nehalem processors claim to have greatly improved the Hyperthreading support, and luckily I just upgraded one of my computers to support these new processors.

My new machine has dual Intel Xeon 5560’s, that’s a total of 8 physical cores running at 2.8Ghz.  My machine contains 24G of Ram and is running WindowsXP64 (I know, it’s old) and Autodesk’s 3D Studio Max 2010. A friend (someone much more experienced at 3dsMax than I) built me a scene that rendered using Mental Ray at a whopping 2600 pixels wide.  The resulting scene rendered to completion in 23 minutes, 45 seconds.

After a reboot where I enabled Hyperthreading, we attempted the render again on the new 16-core configuration.  Exact same setup, just clicked “Render” and it completed in 19 minutes, 14 seconds.

For the math novices out there, that’s a savings of 4 minutes, 30 seconds on the render with nothing but enabling hyperthreading.  That’s a saving of almost 20%!

We’re still doing more tests and benchmarks, but so far the results are promising.  If you have Nehalem processors, try it yourself and post your own results in the comments!

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