Lenovo 3797 manual Ggg eRxff-PC3-wwwwwm-aa-bb-cc

vThe specifications of a DDR3 DIMM are on a label on the DIMM, in the following format.

ggg eRxff-PC3-wwwwwm-aa-bb-cc

where:

gggis the total capacity of the DIMM (for example, 1GB, 2GB, or 4GB)

e is the number of ranks

1 = single-rank

2 = dual-rank

4 = quad-rank

ffis the device organization (bit width)

4 = x4 organization (4 DQ lines per SDRAM)

8 = x8 organization

16 = x16 organization

wwwwwis the DIMM bandwidth, in MBps

6400 = 6.40 GBps (PC3-800 SDRAMs, 8-byte primary data bus)

8500 = 8.53 GBps (PC3-1066 SDRAMs, 8-byte primary data bus)

10600 = 10.66 GBps (PC3-1333 SDRAMs, 8-byte primary data bus)

12800 = 12.80 GBps PC3-1600 SDRAMs, 8-byte primary data bus)

m is the DIMM type

E = Unbuffered DIMM (UDIMM) with ECC (x72-bit module data bus)

R = Registered DIMM (RDIMM)

U = Unbuffered DIMM with no ECC (x64-bit primary data bus)

aais the CAS latency, in clocks at maximum operating frequency

bbis the JEDEC SPD Revision Encoding and Additions level

ccis the reference design file for the design of the DIMM

d is the revision number of the reference design of the DIMM

vThe following rules apply to single-rank and dual-rank DDR3 DIMM speed as it relates to the number of DIMMs in a channel:

–When you install 1 DIMM per channel, the memory runs at 1333 MHz

–When you install 2 DIMMs per channel, the memory runs at 1066 MHz

–When you install 3 DIMMs per channel, the memory runs at 800 MHz

–All channels in a server run at the fastest common frequency.

–Mixing registered and unbuffered DIMMs is not supported.

vThe DIMM options that are available for the server are 1 GB, 2 GB, 4 GB, and 8 GB (when available). The server supports a minimum of 1 GB and a maximum of 128 GB of system memory.

For 32-bit operating systems only: Some memory is reserved for various system resources and is unavailable to the operating system. The amount of memory that is reserved for system resources depends on the operating system, the configuration of the server, and the configured PCI devices.

vA minimum of one DIMM must be installed for each microprocessor. For example, you must install a minimum of two DIMMs if the server has two microprocessors. However, to improve system performance, install a minimum of three DIMMs for each microprocessor.

vThe maximum operating speed of the server is determined by the slowest DIMM in the server.

Chapter 5. Installing optional devices and replacing customer replaceable units 65