This HP 604506-S21 compatible 8GB 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. All of our server memory is built to strict JEDEC standards at one of the tier 1 facilities (Samsung, Micron, or Hynix). Our products are also guaranteed by federal law to not affect or void OEM warranties.

• DIMM 8 GB of memory to heighten your computer's performance
• 240-pin-pin 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 Registered signal and CL9 latency will run them smoothly