Besides the 512MB limit, the i815 boards were some of the most stable P3 around (beside the 440BX). I had my mind set on a FC-PGA2 converter adapter a while back (so that I could use a P3 Tualatin with my older VIA Apollo Pro 133 Socket 370 board), but the idea never ended up pulling through.
More details here: http://www.calpoly.edu/~mkou/comp.html OK, so the P4 is not quite retro yet, but it's the oldest thing I still have at home (unfortunately I either sold most of my older hardware or recycled it several years ago). Mobo: VIA P4XB-S (the page above is a bit out-of-date; I have since …