PowerEdge 2650 Memory Questions

PowerEdge 2650 Memory Questions

1.      What type and size memory can I install in my system?

2.      What memory features does the PowerEdge 2650 support?

3.      Memory Module Installation Guidelines

4.      Why Does my operating system only see 256MB available memory?

5.      Spare Parts and Upgrade

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1.       What type and size memory can I install in my system?

The PowerEdge 2650 supports up to six PC1600 (DDR200) or PC2100 (DDR266), in 128MB, 256MB, 512MB, 1GB and 2GB DIMM sizes, for a total memory capacity of 12GB, depending on the type of motherboard that shipped in each model.

Originally, the PowerEdge 2650 server series shipped with motherboards that supported a 400MHz Front Side Bus (FSB), and could support either memory type, but a 1GB maximum DIMM size, 6Gb total capacity.

Later in the production cycle, the motherboards were upgraded to 533 MHz FSB and will only run PC2100 with a maximum DIMM size of 2GB, 12Gb total capacity.

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2.       What memory features does the PowerEdge 2650 support?

The PowerEdge 2650 memory interface supports memory scrubbing, single-bit correction and multi-bit error detection.

Memory Interleaving
The memory system supports 2-way interleaved memory configurations to reduce latency compared to non-interleaved implementations.

The 6 DIMM sockets are divided into three memory banks.

To support memory interleaving the memory capacity must be identical within a given bank, however, the capacities for two separate banks can be different.

Non-interleaved mode is supported for troubleshooting purposes, when only a single DIMM is available. The system will complete POST and boot to an OS with only one DIMM when installed in Socket Bank 1 DIMM A (closest to the power supplies).

Spare Bank Memory
Your system features redundant memory, called which provides the system with a failover memory bank when an active memory bank has excessive single-bit errors.

This failover occurs without the need to halt or restart the system. You can enable this feature in the System Setup program.

For more information about the System Setup program, see your User's Guide <ADMIN NOTE: Broken link has been removed / replaced from this post by Dell>.

To enable the Redundant Memory option in the System Setup program, all memory slots in the system must be populated, and all memory modules must be of the same type and size.

The redundant memory options vary according to the number of populated memory banks and whether identical memory modules are installed in each bank:

• Disabled — One or more banks are not populated, or not all memory modules are of the same type and size.
• Disabled and Spare Bank Enabled — All three memory banks are populated with memory modules of the same size and type.

Chipkill
The PowerEdge 2650 supports chipkill on only the 512MB, 1GB and 2GB DIMMs.

ChipKill support enables the system to avoid uncorrectable data errors if a DRAM device fails.

This is accomplished by spreading 2 144-bit ECC works across 4 DIMMs (32 bytes). Each ECC work has the capability of correcting any single bit error on any four adjacent bits.

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3.       Memory Module Installation Guidelines

For optimum performance, install the memory modules starting with the first connector (closest to the power supplies) and leave no open connectors between installed memory modules.

You must install memory modules in matched pairs.

Install identical memory modules in connectors A and B for bank 1 before installing modules in connectors for bank 2, and so on.

More information can be found in the Removing and Replacing Partssection of the PowerEdge 2650 Service Manual <ADMIN NOTE: Broken link has been removed / replaced from this post by Dell>

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4.       Why Does my operating system only see 256MB available memory?

A function called "OS Install Mode" is currently enabled in the system BIOS.

This function limits the amount of system RAM available to the operating system to 256MB, and is necessary for installations of older operating systems to complete.

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5.       Spare Parts and Upgrade

Below are Dell part numbers for various DIMMs we offer for the PowerEdge 2650. These modules must be PC1600 (400MHz FSB motherboard only) or PC2100 compliant ECC-Registered DIMMs.

Notes:
Non-registered and Non-ECC DIMMs are NOT supported in the PowerEdge 2650.
PowerEdge 2650 memory must be installed in matched pairs, order the 5 digit part numbers in quantities of 2.
5 Digit part numbers come from warranty service stock rooms which are labeled "Refurbished", but in the majority of cases are in fact new parts.
7 digit part numbers (Customer Kits) are always new parts.

PC1600 (DDR200) 400MHz FSB motherboard only

27YNY       128MB DDR,200MHZ,1X128 DIMM
6J226       256MB DDR,200MHZ,1X256 DIMM
501JU       512MB DDR,200MHZ,1X512 DIMM
632EX       1GB DDR,200MHZ,1X1GB DIMM

PC2100 (DDR266) Both motherboard types
These Customer Kits include 2 matched DIMMs in each kit.
311-3059       256MB DDR,266MHZ,2X128 DIMMs
311-3060       512MB DDR,266MHZ,2X256 DIMMs
311-3067       1GB DDR,266MHZ,2X512 DIMMs
311-3066       2GB DDR,266MHZ,2X1GB DIMMs

PC2100 (DDR266) 533MHz FSB motherboard only
311-3068       4GB DDR,266MHZ,2X2GB DIMMs

Please note that the contents of the above part numbers are subject to change over time, as is availability of those parts.

We recommend contacting our Spare Parts department at 1-800-372-3355 for pricing, availability, and purchasing of all the above parts.

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