Lenovo TD100X manual Installing a memory module

Installing a memory module

The following notes describe the types of dual inline memory modules (DIMMs) that the server supports and other information that you must consider when installing DIMMs:

vThe server supports industry-standard, 1.8 V, 240-pin, 667 MHz, PC2-5300 double-data-rate 2 (DDR2), dynamic random-access memory (DRAM) with error correcting code (ECC) fully buffered dual inline memory modules (DIMMs). These DIMMs must be compatible with the latest DDR2 667 MHz DRAM fully buffered DIMM specification. For a list of options for the server, see http:// www.lenovo.com/accessories.

v(ThinkServer TD100 models) The DIMM options that are supported for the server are 512 MB, 1 GB , and 2 GB in x4 or x8 technology, single-rank or double-rank. The server supports a minimum of 1 GB and a maximum of 32 GB (reduced to 16 GB in mirrored mode) of system memory.

v(ThinkServer TD100x models) The DIMM options that are supported for the server are 1 GB, 2 GB, and 4 GB in x4 or x8 technology, single-rank or double-rank. The server supports a minimum of 1 GB and a maximum of 48 GB (reduced to 24 GB in mirrored mode) of system memory.

vThe system board provides eight or 12 functional DIMM connectors (depending on the model) and supports two-way memory interleaving when DIMMs are installed in pairs.

Note: DIMM connectors 3, 6, 9, and 12 are not functional for ThinkServer TD100 models. Do not install DIMMs in these four connectors and do not remove the DIMM thermal baffles installed in these connectors unless you need to replace the system board.

vWhen installing multiple pairs, always install the DIMMs with the most capacity in the first slots. For example, if you had a pair of 1 GB DIMMs and a pair of 4 GB DIMMs, you would install the 4 GB DIMMs in slots 1 and 4.

vThe memory controller has four fully buffered DIMM channels that are organized into two branches. Each branch has two channels and each channel controls two DIMMs. DIMMs that are next to each other (for example, DIMM connector 1 and DIMM connector 4) within the channels of a branch must be identical in size, type, speed, and technology. However, the DIMMs in the connector above or below each other within the channels of a branch do not have to be identical (for example, the DIMMs in DIMM connector 1 and DIMM connector 2 do not have to be identical). The following illustration shows how the memory controller is organized into branches and channels with a pair of DIMMs installed in each branch.

DIMM 3 DIMM 2 DIMM 1

DIMM 6	DIMM 9
DIMM 5	DIMM 8
DIMM 4	DIMM 7

DIMM 12

DIMM 11

DIMM 10

Channel 0	Channel 1		Channel 2	Channel 3
Branch 0			Branch 1
		Memory Controller

vThe server can operate in two major modes: mirroring and non-mirroring (normal). The server can also operate in a single-channel mode when one DIMM is installed.

98ThinkServer TD100 and TD100x: Hardware Maintenance Manual