Top RAM: Manufacturer: Kingston Model Number: KVR1333D3S8N9/2G (from ValueRAM category) Capacity: 2GB Type: DDR3 Speed (Frequency): 1333 MHz Voltage: 1.5V CAS Latency: CL9 (based on the N9 code in the model) Usage: For desktop computers (Desktop - DIMM). Bottom RAM: Manufacturer: Kingston Capacity: 2GB Type: DDR3 (indicated by PC3) Speed (Frequency): 1066 MHz (because PC3-8500 bandwidth corresponds to 1066 speed) Rank: 2Rx8 (meaning it's Dual Rank) Sub-type: Unbuffered DIMM (indicated by U in 8500U), also intended for desktop computers.