Where did you get LGA1155 mini-ITX for $40 ($2000 * 0.02) with some sensible IvyBridge CPU?, RAM and so on?
The nice thing about second hand computer parts is that they work exactly as good, but cost a half to a third of the new one.
The new price came out to something about $80, the second hand price was between $30 and $50 per board (CPU, board, Fan, RAM)
I already had a bunch of PicoPSUs and DC-DC converters (the whole thing runs off a 24V bus i have) laying around, so that trims the cost as well.
CPUs are G1610, G2020, G2030, G1620 - low-end Celerons and Pentiums with 2 cores each and 2.6 to 3.0 GHz.
Core to core they are 1.5 times as fast as an i7 920 running at 2.6GHz, but the latter got 4 cores and HT, putting it ahead.
I wouldn't expect much raw computing power from your setup. It is cluster like, IO severely limited by the gigabit ethernet (!= InfiniBand) and it is CPU only.
Depends on the task. Right now i do raytracing experiments on it, which needs about zero communications, and the speedup is 3.75x the i7 alone.
Another thing i tried is magnetic field computation, which is also a zero-communication task.
Naturally, such tasks can run a thousand times faster on a GPU, but the GPUs are somewhat awkward to program, have limits in complexity and data size, and don't come in small, low power consumption and low cost packages.
In the end, it's not intended to be something practical, but just a for fun experiment driven randomly.
If I might ask where did the boards come from?
A variety of local sources of the "garage sale" and "direct advertisement" kind.
The nettop is an unrelated thing i had for a while, which just fit neatly in the spare space.