If you haven't read Christopher Hoff's "Rational Survivability " blog, you're in for a treat. He's a bourbon and whiskey-drinking, red meat-eatiing, cigar-smoking security coot. (He's even pissed off Simon Crosby too.) In his latest post, Hoff asks whether big iron is dead, or whether it ever even left? His point is that while we've been focusing on smaller servers working together as one, distributed loads, etc., virtualization is changing that game and now we want the big stuff again.
I've seen this first-hand over the past ten years. I remember that people used to buy 8U, 8 Pentium Pro processor servers all the time. But then it seemed like everything switched over to dual processor, 5GB RAM servers. (Especially considering you could usually buy four 1U servers for much less than single larger server that had the same amount of processors / RAM.
But now that we're virtualizing everything, I guess all that money on things like RAIDed RAM is finally worth it again?