Processor/Memory Subsystem

3.3Memory Subsystem

All models support non-ECC DDR3-1066 (PC3-8500) and DDR3-1333 (PC3-10600) memory modules. CMT, MT, and SFF form factors support up to 16 gigabytes of memory while the USDT form factor supports up to 8 gigabytes of memory.

✎DDR2 memory modules used on previous systems are not compatible with these systems. DDR3 Ultra Low Voltage (DDR3U) memory modules are also not compatible with these systems and can be damaged if installed.

■DIMM1, channel B (black socket)

■DIMM2, channel B (white socket)

■DIMM3, channel A (black socket)

■DIMM4, channel A (white socket)

Memory modules do not need to be installed in pairs although installation of pairs (especially matched sets) provides the best performance. Black sockets must be populated first. The BIOS will detect the module population and set the system accordingly as follows:

■Single-channel mode - memory installed for one channel only

■Dual-channel asymetric mode - memory installed for both channels but of unequal channel capacities.

■Dual-channel interleaved mode (recommended) - memory installed for both channels and offering equal channel capacities, proving the highest performance.

These systems support memory modules with the following parameters:

■1.5 volt SDRAM DIMMs

■Unbuffered, compatible with SPD rev. 1.0

■512-Mb, 1-Gb, and 2-Gb memory technologies using x8 or x16 devices

■CAS latency (CL) of 7 for 1066-MHz memory and CL of 9 for 1333-MHz memory

■Single or double-sided DIMMs

■Non-ECC memory only

The SPD format supported by these systems complies with the JEDEC specification for 128-byte EEPROMs. This system also provides support for 256-byte EEPROMs to include additional HP-added features such as part number and serial number.

If BIOS detects an unsupported memory module, a “memory incompatible” message will be displayed and the system will halt. These systems are shipped with non-ECC modules only.

An installed mix of memory module types is acceptable but operation will be constrained to the level of the module with the lowest (slowest) performance.

If an incompatible memory module is detected the NUM LOCK will blink for a short period of time during POST and an error message may or may not be displayed before the system hangs.

3-4

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Technical Reference Guide