Its ECC server ram and its DDR2 so nothing made in the last few years can use it. This auction had a partial list of compatible systems(http://www.ebay.com/itm/2-GB-Hynix-2GB-2Rx4-PC2-5300F-555-11-398707-051-39M5790-38L5905-39M5791-/220943572056)
Apple Xserve Xeon 5100
ASUS DSBF-D
ASUS DSBF-D/1U
ASUS DSBF-D12
ASUS DSBF-D12
ASUS DSBF-D12/SAS
ASUS DSBF-D12/SAS
ASUS DSBF-DE
ASUS DSBF-DE
ASUS DSBF-DE/SAS
ASUS DSBF-DE/SAS
ASUS DSBV-D
ASUS DSBV-DX
ASUS DSBV-DX
ASUS DSBV-DX/C
ASUS DSBV-DX/C
ASUS DSGC-DW
ASUS DSGC-DW
ASUS DSGC-DW/SAS
ASUS DSGC-DW/SAS
ASUS RS160-E4/PA4
ASUS RS162-E4/RX4
ASUS RS260-E4/RX8
ASUS TS700-E4/RX8
ASUS TS700-E4/RX8
Compaq ProLiant BL460c
Compaq ProLiant BL480c
Compaq ProLiant BL680c G5
Compaq ProLiant DL140 G3
Compaq...