All PowerEdge 1800 system boards support PC2-3200 (400MHz) DDR2 fully-buffered, ECC-registered memory DIMMS when installed in matching pairs. All system boards will support up to six 2GB DIMMS for a maximum of 12GB RAM with the current BIOS revision.
Dell part numbers for memory normally signify individual DIMMs, whereas third-party memory like Kingston sometimes come in kits of two DIMMS. Check product description for details.
If you need assistance with installing memory modules, please see Dell's instructions below.
All prices are in USD.