4gb 1x4gb configuration of ddr3 1600 non ecc ram dimms boost the capabilities of your hp workstation and keep it performing reliably with hp memory upgrading your memory is a cost effective way to improve system performance when insufficient memory and hard drive paging is slowing your applications down hp ddr3 4 gb dimm 240 pin 1600 mhz pc3 12800 unbuffered non ecc for workstation z1 z220 z230