Hey guys,
There was a topic on this forum about Render Pockets render farm build using Ikea Helmer case. At the end of the topic there was a question about Intel Xeon-D for rendering in such a cluster. I'm watching this CPU since beginning and finally got a small rack server from Supermicro to do some testing!
The server is build using this motherboard:
http://www.supermicro.com/products/motherboard/xeon/d/x10sdv-f.cfm, 32GB of RAM installed with two DDR4 2133MHz Hynix memory modules and some Samsung SSD drives. This is the server I'm using for test:
http://www.supermicro.com/products/system/1U/5018/SYS-5018D-FN4T.cfmThe last post is from March 2015 and conclusion from Juraj is that Intel Xeon-D is a slow CPU:
There is no magic on how to squeeze more performance with lower TDP under same architecture. So this is no miracle, it is exactly what it is, a slow CPU.
Well it's not. I'm blown away by the results. To add some context. My workstation is build on Intel Coore i7-4790K overclocked to 4.6GHz with Asus Maximus Hero VII motherboard and 32GB of DDR3 memory running at 2133MHz (Corsair Dominator Platinum). Everything is watercooled - after 24 hours on rendering CPU is at 62degC max. Now that is the result of rendering test scene with Corona 1.3 on my workstation:

With full load this workstation is pulling 340W from the wall socket with Titanium class power supply. Now prepare to be blown away! This is the same benchmark on Intel Xeon-D 1540 - 8 cores, 16 threads, 2.3GHz at all cores while rendering (potential is to go up to 2.6GHz single core).

4.4mln rays/sec! 10% more than my overclocked i7-4790K. And now the fun part - this whole server is pulling 95W from wall socket at full load with Gold class power supply. The CPU is only 35W TDP which means you can cool it with passive radiator only.
Why there is such difference? First of all i7-4790K is 22nm and Xeon-D is 14nm lithography which means that you can run it with smaller voltages and lower heat. Second thing is Xeon architecture - Xeon-D is designed for server with all the goodies like AVX2 which is lightning fast on this CPU.
Sorry Juraj - you were wrong ;) This is the new king for rendering if you consider performance per W and performance per $$$. I was hopping to get something cool from this CPU but newer expected to get so much performance!