I stumbled upon four pieces of 4GB PC2 5300F RAM from IBM (Part Number 43X5061). In my Dell Poweredge 1950 Rev 2 server there currently are two 512MB sticks, which appear to have the same specifications as my four new sticks of RAM. They all say PC2-5300F-555-11 on them.
I can't get the server to register the 4GB sticks. I know that my server supports sticks of this size, and I've tried putting them in the server paired (according to Dell documentation), unpaired, and mixed both kinds of RAM. When I put in only 4GB sticks there is no screen output, and the status display says "E2010 No Memory".
If I put in both 512MB and 4GB sticks, I do get BIOS output but the server refuses to pass POST, citing "The following dimm is not compatible with memory controller", followed by a list of the sockets with 4GB sticks in them. I've tried all possible permutations of RAMs and sockets, and I'm honestly stumped.
The only noticeable difference between the 512MB and the 4GB sticks are that the 4GB ones have an IBM part number on them, while the 512MB ones only have the hynix label. Does Dell servers not actually support IBM-labeled memory? Is my RAM broken?
Here's a picture of the two different sticks side by side: