PowerEdge 840 memory upgrade.

PE 840 cannot take Fully-Buffered DIMM's.  They must be DDR2, 533/667, Unregistered/Unbuffered, ECC.

http://www.ec.kingston.com/ecom/configurator_new/modelsinfo.asp?SysID=33063&mfr=Dell&model=PowerEdge+840&search_type=&root=us&LinkBack=http%3A%2F%2Fwww.kingston.com&Sys=33063-Dell-PowerEdge+840&distributor=0&submit1=Search

"To use fully buffered DIMMs, your server or motherboard must use FBDIMM architecture. An FBDIMM will not fit into a standard DDR2 socket, and a DDR2 module will not fit into an FBDIMM socket."

"The notch in a 240-pin fully buffered DDR2 DIMM is in a different location than the notch for regular 240-pin DDR2 modules."

http://www.crucial.com/store/mpartspecs.aspx?mtbpoid=F27D0DCDA5CA7304

The 840 does use DDR2 memory so not sure why the memory doesn't physically fit into the server. The memory that you do have is fully buffered or registered so it will not work in the 840. It will only work with the unbuffered DDR2 ECC.

Thank you all!

THEFLASH1932, later I saw the link to the Crucial site with the explanation! I  will have the sticks exchanged one week from now.

Thanks again!

Carlos Vaz

ummm I got 3 gigs of PC2-5300U in mine

Because that is supported memory.  5300 is 667MHz, U stands for Unbuffered/Unregistered.

you do get odd balls that have the notch in the wrong place.

The notch isn't a mistake - it is not an 'oddball' - the notches are there to prevent incompatible memory from being inserted.

ummm I got 3 gigs of PC2-5300U in mine, it boots and runs, you get an error now and than, I worked around that by turning memory checking off in the bios. I'd imagine it doesn't fit because DDR2 is a specification not a kind. you do get odd balls that have the notch in the wrong place.