Its best to match the speed at which you know your motherboard will operate.
Which motherboard (computer model number would suffice) do you have?
- DDR2-533
- DDR2-666
- DDR2-800
- DDR2-1066
System memory features
- Four 240-pin Double Data Rate 2 (DDR2) SDRAM Dual Inline Memory Module (DIMM) connectors with gold-plated contacts
- Non-ECC, 1.8V, DDR2 800/667 MHz memory