I want to get another dual Ppro board one of these days (maybe another Intel PR440FX) to run old UNIX/Linux on. My current unit used to be my main server (Dual PPro overdrives with 4x256MB EDO ECC Buffered DIMMs), that unit will get downgraded to NT4 from Win2k. If I did get another unit (snagged some more of that special RAM from ebay) I would want the black heatsink PPro 200's with 1MB of cache onboard (they did 256K,512K and the rare 1MB).
Years ago I lusted after the Gateway 6x PPro servers but they seemed to not benefit that much with 6 processors and you could not use the PPro upgrades in anything with more then 2 CPUs. I guess it was the best they could do at the time. With NT you can assign a running application to a specific CPU or just let NT dump a process to the next CPU in line as needed. The problem I guess is memory bandwidth on systems that old and all the overhead of multiple CPU's that need to be fed things to do.
I have a dual PPro board from an IBM machine that I (foolishly) took apart, converted into a luggable, burned out a modern expensive video card, and then threw away the case remains... Anywho I have a board. I also have CPUs. I'd sell 'em. (This was a workstation machine, 765GL or something?)
It can be bus-dependant as well. NT4 supported microchannel (correctly after SP3), but W2K Server does not. So I can have a nice, fully-equiped mixed MCA/PCI bus Server 320, 520, or 720 (the last with up to six Socket 5 CPUs and 512Mb of RAM, or five Socket 5 CPUs and a gig of RAM, of course you need the Enterprise version of NT to have above four CPUs) without being able to get past NT.
I stay away from Microchannel systems - I sell them, and the cards, whenever I get them. Don't like how hugely incompatible with most of my stuff they are, and I hate how PS/2s (which are almost all that has MCA) have the BIOS setup requiring a disk, which requires a working drive and and the right files, and so on... They won't even boot when you get them without this disk if the battery died, and the battery can't be easily replaced 'cuz it's always in a Dallas unit... Even with the disk I never got one to boot (cept the Model 25 but that's an ISA box).
Edit: Looking at that box I might have to pass on it just because of weight. I certainly can't afford it at the moment either way, but that monster looks like it will cost a damned fortune to ship. With a Socket 5 system I'd have to hunt down VRMs to max the system out and the SIMMs would be constrictive because I see 32MB SIMMs and 128MB SIMMs (even if it takes them, which it probably doesn't) would cost quite a bit to fill it with. If it had had a standard AT or ATX board Id've probably tried to get it from ya without the case, but it's a proprietary build with a tall riser, etc. Anywho my point is I can't really get this particular box from you - it's very cool, and if you lived within reasonable driving distance I'd probably take it, but I can't afford to pay for something that big and heavy that won't be absolutely perfect to max out - nice thing about a 486 box, if I got my hands on a MP one of those, is I can use (relative to Pentium VRMs) easy to get upgrade chips.
Point is it would end up costing me $200 or so before I even paid for the machine - and I can't afford that. :/