In the 'old days' of pre-BOINC SETI, individuals ran SETI on any old PC they could get their hands on. In the very early days this included Pentium II CPU's running at 200MHz !
Whilst I was soon using any old / obsolete PC that came my way, the breakthrough came when I found 'job lots' of motherboards on eBay. The problem was, that whilst 'previous generation' motherboards and CPU's where (relatively) cheap, hard drives were a lot more expensive. So I soon started looking for a way to run SETI on motherboards with no hard disk. In fact, I ended up placing them on a shelf without even a case !
Of course, eventually SETI left the older Operating Systems behind and it became too difficult to make my Distributed Computing farm 'BOINC' compatible. Once SETI started to run on CUDA Graphics cards, the whole 'compute node' approach became redundant (it was now a matter of how many CUDA cards you could fit onto a motherboard, not how many motherboards you had)
I leave these pages here mainly for their historic interest
The pages in this topic are :-