HP Z Virtual Memory configurations

Item	Description	Definition
		x8 = 8-bit
4	Voltage rating	L = Low voltage (1.35v)
		U = Ultra low voltage (1.25v)
		Blank or omitted = Standard
5	Memory speed	12800 = 1600-MT/s
		10600 = 1333-MT/s
		8500 = 1066-MT/s
6	DIMM type	R = RDIMM (registered)
		E = UDIMM (unbuffered with ECC)
		L = LRDIMM (load reduced)
		H = HDIMM (HyperCloud)

For the latest supported memory information, see the QuickSpecs on the HP website (http:// h18000.www1.hp.com/products/quickspecs/ProductBulletin.html). At the website, choose the geographic region, and then locate the product by name or product category.

Memory configurations

To optimize server availability, the server supports the following AMP modes:

●Advanced ECC—provides up to 4-bit error correction and enhanced performance over Lockstep mode. This mode is the default option for this server.

●Online spare memory—provides protection against failing or degraded DIMMs. Certain memory is reserved as spare, and automatic failover to spare memory occurs when the system detects a DIMM that is degrading. This allows DIMMs that have a higher probability of receiving an uncorrectable memory error (which would result in system downtime) to be removed from operation.

Advanced Memory Protection options are configured in RBSU. If the requested AMP mode is not supported by the installed DIMM configuration, the server boots in Advanced ECC mode. For more information, see "HP ROM-Based Setup Utility on page 86."

The server also can operate in independent channel mode or combined channel mode (lockstep). When running in lockstep mode, you gain reliability in one of two ways:

●If running with UDIMMs (built with x8 DRAM devices), the system can survive a complete DRAM failure (SDDC). In independent channel mode, this failure would be an uncorrectable error.

●If running with RDIMM (built with x4 DRAM devices), the system can survive the complete failure of two DRAM devices (DDDC). Running in independent mode, the server can only survive the complete failure of a single DRAM device (SDDC).

Table 5-1Maximum capacity

DIMM type	DIMM rank	One processor	Two processors
RDIMM	Single-rank	96 GB	192 GB
RDIMM	Dual-rank	192 GB	384 GB

42 Chapter 5 Hardware options installation