One of my favourite candidates was to use the brand new Biostar A68N-5600, that packs a 25W A10-4655m with 4 cores. This board has a pretty reasonable price for new hardware and it has a very modern look for the aesthetics of the whole system. Although the processor does not have a top performance, it packs a small but decent GPU which can be used to test some OpenCL programming. Unfortunately the rising prices of DDR memory and the need to add hard drives and power supply made my nodes over the 150€ . I even considered using >span class="J-JK9eJ-PJVNOc" data-g-spell-status="2" id=":1p2.16" tabindex="-1" role="menuitem">usb drives to boot the OS to save in costs.

A second favorite was to get some ultra small form factor second hand desktop PCs, the kind of stuff that uses your dentist secretary. Big companies use hundreds of this modests pcs, and some of them pack quite some performance. Talking about performance: since I can not test the hardware before it is shipped, and they wont ship before I pay... I have very little means to do objective performance assessments. For this reason I have developed a very un-scientific and un-recommended technique: get the score in www.cpubenchmark.net and multiply by the number of nodes. I presume that the real score is under this metric, as we will be introducing latencies in the networking and software layer. In other words: This whole computer could be faster by using one of the new high end processors. We could even buy one with a lot of cores, but it would not be as fun, or would it? 

I managed to find some Dell Optiplex 7010 USFF (ultra small form factor) which come already with 8Gb DDR3, some hard drive of some kind and a gold-rated power supply each, for little less than 150 each. They come with a i5 third generation that scores 6341 in the benchmarks, giving me enough muscle to feed most of my software projects.

I budgeted 200€ for the switch, wires and materials for the boxing, and while we wait for the delivery I started doodling the case.