HP ProLiant Intel-based 100-series G6 servers

The three memory channels between each processor’s integrated memory controller and its dedicated

DDR3 memory provide a total bandwidth of 32 GB/s.

On-DiMM thermal sensors

HP DDR3 DIMM mod

ules incorporate an integrated thermal sensor that signals the chipset to throttle

memory traffic to the DIMM if its temperature exceeds a programmable critical trip point. Using the

data from these thermal sensors, HP has engineered ProLiant G6 servers to reduce fan speed when

memory is idle, effectively reducing power consumption. The BIOS in ProLiant G6 servers verifies the

presence of the thermal DIMM sensor during POST. Some third-party DIMMs may not include this

thermal sensor. If it is absent, a POST message will warn that the DIMM does not have a thermal

sensor, and the fans will be forced to run at higher speeds (requiring more power).

DIMM choices

DDR3 is available as both Unbuffered Dual In-line Memory Modules (UDIMMs) and Registered

(buffered) Dual In-line Memory Modules (RDIMMs). Both RDIMMs and UDIMMs support error

correcting code (ECC).

There are three types of DDR3 available for ProLiant G6 servers:

 PC3-8500R (RDIMM, ECC compliant) —1066 or 800 MT/s data rate, depending on memory

configuration and processor installed.

 PC3-10600E (UDIMM, ECC compliant) —1333, 1066, or 800 MT/s data rate, depending on

memory configuration and processor installed.

 PC3-10600R (RDIMM, ECC compliant) —1333, 1066, or 800 MT/s data rate, depending on

memory configuration and processor installed.

Low-voltage DDR3

Customers ca

n take advantage of the HP low voltage (LV) DDR3 memory option. LV memory can

operate at 1.35 V, reducing power and cooling requirements. Some LV DIMM configurations can

affect performance. The difference occurs in 2 DIMM per channel (DPC) configurations with dual-rank

DIMMs. In these configurations, the memory bus runs at 1.5 V with 2 DPC at 1333 MT/s, or 1.35 V

with 2 DPC at 1066 MT/s. This results in a 20% reduction in bandwidth for the lower voltage. In all

other HP LV configurations, the LV data rate is the standard 1.5V data rate. The BIOS determines the

DIMM population from the system and the operating voltage and data rate capability from the

DIMMs. The BIOS then sets the data rate based on that information.

NOTE:

Although the bandwidth reduction from DDR3-1333 to DDR3-1066 is 20%, the

measured reduction in throughput is 10%

Single rank DIMMs, configured at 1, 2, and 3 DPC, and dual rank DIMMs, configured at 1 and 3

DPC, run at the 1333 MT/s data rate at both voltages.

ProLiant G6 and G7 server models with Intel 5600 Series processors support LV memory:

 PC3L-10600R—1333, 1066, or 800 MT/s data rate, depending on memory configuration.

Low power DIMM kit

he Low Power (LP) kit runs at standard voltage, but uses a different configuration (Quad ranked,

lower performance DIMMs) than the standard 4GB DIMM. Based on this configuration, the LV DIMMs