This HP A0R59A compatible 16GB DDR3-1333MHz Dual Rank Registered ECC 1.35V 240-pin CL9 factory original RDIMM is 100% guaranteed to be compatible with your system and to work right the first time. Adding additional memory is the best way to increase the performance of your system. All our memory is built to strict JEDEC standards to meet or exceed the Tier 1 OEM's factory requirements. Our products are also guaranteed by federal law to not affect or void OEM warranties.

• DIMM 16 GB bar will run multiple applications together and enhance your computer's performance
• DDR3 SDRAM interface synchronizes electrical and clock signals for an efficient data transfer rate
• No matter how heavy and numerous the applications that you are using, 1333 MHz memory speed with CL9 latency will run them smoothly