It's not just the total wattage, but the amperage on the 12-volt rail, that both processors and memory pull from. There is a list of power supplies (and non-Intel chassis) that do work with dual processors and full memory, at
http://www.intel.com/support/motherboards/server/s5520sc/sb/CS-030490.htm for the SC and
http://www.intel.com/support/motherboards/server/s5500BC/sb/CS-030486.htm for the BC
Thanks for the suggestion. I may have missed something but I wasn't able to find any power ratings for any of the mentioned PSUs, following those links, even the Intel ones.
However, I tried the Power_Budget_Tool spreadsheet linked elsewhere and according to that it should only use about ~30 amps to get either board+ 2 x CPU + memory to POST (everything else disconnected). My PSU provides 62 amps on the 12v rail, so that should be adequate.
The memory I'm using is KVR1066D3E7/1G which is not on the tested list but it seems pretty similar to KVR1066D3E7S/1G which is, the only difference being the lack of a thermal sensor, so I think that should be fine too?
Yes, 62 amps should be sufficient. Do those boards also have one or two additional 2x4 power plugs for the processors? I can't remember.
For the memory, well, if it's not on the tested list, funny things can happen. I think for Kingston specifically, all the memory that *doesn't* act funny on the Intel boards has an "I" at the end.
The S5500BC has 1 x 8 pin, the S5520SC has 2. I'll try with a 1200W PSU with 2 x 8 pin power before I RMA the boards, just to be sure, even though I had planned on using a splitter for the S5520SC.
Hi i have the s5520sc board and corsair psu hx1000 ,i notice that the psu dont have auxiliary power connector and maybe for this reason cpus and ram dont work properly.
So in my case i believe i damage the cpu 2 because i have unrecovable fatal error speeds missmatch ,in bios the cpu2 run at 4400!!!!! i dont do anything at all (i promise 
) so i think that cpu takes more power and alleluia.....http://www.google.gr/search?hl=el&client=firefox-a&hs=c2Q&rls=org.mozilla:el:official&sa=X&ei=fx0ZTpGxHcea-wbC_OzXBw&ved=0CCsQBSgA&q=alleluia&spell=1
I really dont undrestand why this happent cause dont happent always...for one hour the cpus dont have speeds missmatch and after a while they have....
in my country we say "malakies" for these situation.
You may want to update the BIOS code stack.
This sounds like an intermitted issue in one of the old bios versions.
(and it really is not running at that speed 
)
