Passmark Benchmark - Relevant?

Having gotten my head around the pros & cons of GPU rendering, I’ve been doing a bit of research on CPUs and power efficiency, am wondering how relevant this Passmark Benchmark
http://www.cpubenchmark.net/high_end_cpus.html
is, to the world of Blender? Is it a good reflection of the kind of performance I can expect in scene rendering with cycles/luxrender?

Did a quick cost-calc for rendering a good-sized animation on Amazon’s EC2, it was phenomenally expensive; high enough to warrant looking into building a small(ish) personal render farm. But there are limitations - electrical for instance. I’d be basically limited to a 1600watt circuit from a standard North American wall socket.

March 07/2012 - Intel has released its new Sany bridge E5-2600 series Xeons, based on what I’m reading, they are easily surpassing anything else out there.
http://www.anandtech.com/show/5553/the-xeon-e52600-dual-sandybridge-for-servers/11
Looks like there are a couple of low-voltage versions coming on-stream eventually


the E5-2650L with 8-cores/16-threads, and a TDP of 70 watts looks like the tip of the sword, if you have the coin to make it happen.

So I’ve started looking for the most power-efficient (FLOPS-per-watt, I guess) way to build render nodes (capable of at least 32G of RAM). Based solely on the Passmark numbers & TDP from Intel, it looks like the low-voltage Xeon E3-1260L supplies the most performance per watt, ATM. Of course, other hardware plays a role in total power consumption, but I am assuming that they would all be built around comparable specs (as far as power draw is concerned).
The absolute best efficiency (by quite a bit) I’ve seen so far is for the mobile Corei7-2860QM, but it’s got an oddball socket, and appears to be limited to 16GB RAM (Supermicro makes an “embedded” motherboard for this socket). At the moment, the only mobile Corei7 for sale at Newegg is the 2720QM, which is almost exactly equal in efficiency to the Xeon E3-1260L.

What I haven’t been able to find are benchmarks for less common CPUs. VIA Quadcore, Vortex86/XCore86, maybe even Arm (if Blender/Luxrender/etc will even run on these). There are a few ultra-low-voltage VIA Nano CPUs in the benchmark chart above, which perform quite poorly, but nothing recent from VIA. Is anybody employing this end of the CPU market to render scenes?