PE1950 Quad-Processor Problems - "Unsupported CPU combination"

Hello,

Recently we've wanted to upgrade our PE1950 with quad-core processers but have hit a road block. Hopefully someone in the Dell Community can kindly recommend something we can try that may work...

Basically after the decision was made to upgrade the system to quad-cores, we upgraded the BIOS (and everything else) to the latest version (BIOS 2.3.1) which has compatibility for the Harpertown E5400. We then purchased two E5400 processors but after installing them, we received an "Unsupported CPU combination System halted!" error. It was like this with one processor as well.

We then wrote our Dell sales liaison and they recommended that we purchase the Clovertown L5300 series. The recommendation had come from a PowerEdge Brand Manager after providing our Service Tag, etc. After these didn't work, we wrote our liaison again and they apologized and basically suggested that return our upgrades and sell the system on eBay. This surprised us, but not being the ones to give up, we're still seeking definite answer before we just buy a second dual-core and use it for light duty virtualization.

Thank you!

Original CPU: SL9RX - 5130 - 2GHz
BIOS - 2.3.1
PERC 5/I - 5.2.1-0067
Baseboard Management - 2.10
Backplane Firmware - 1.05