I was setting up our BL 480c Blade servers in our c3000 Enclosure and I had installed 64 Gig of RAM in the systems. When it booted to POST it would only show 48 Gig but within the BIOS and Server Manager on the 2008 Server it would show the 64 Gig like it was suppose to have. I checked the slots the RAM was in and those was correct as you really need to pay attention when adding RAM to these servers or you will get the wrong slots and have this problem. I also verified in BIOS that the server was Advanced ECC Support and not in Mirrored memory Mode or online Spare Mode.
What I ended up doing was having to put the server into maintenance mode and having all but 2 pairs removed from the server. Setting the NVRAM dip switch number 6 to on starting the blade and letting it come to post then shutting it down and then turning Dip switch number 6 to the off position and then adding the rest of the RAM to the system and life was good. So steps was
Remove extra RAM
Set the Dip Switch number 6 to on
Power on the server to Post
Shut server down
Add the rest of the RAM
Start Server life was good.
Til later just Roger