Cisco Cisco UCS C22 M3 Rack Server White Paper

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DIMMs qualified by Cisco are manufactured using PCB that the Joint Electron Device Engineering Council

defines as meeting all requirements for performing the most stressful operations. This includes 30

microinches of gold on the DIMM fingers. Flash gold, or 15 microinches of gold, is used on nonqualified

DIMMs.

2. Cisco UCS warranty policy is void with nonqualified memory

Because of the severe technical problems inherent in using nonqualified DIMMs with Cisco UCS servers, Cisco

cannot provide field and warranty support for nonqualified DIMMs or Cisco UCS servers that use those DIMMs.

Cisco support may require users to replace any nonqualified memory with qualified memory prior to providing

support.

3. Cisco UCS Manager is not compatible with nonqualified memory

Cisco UCS Manager and other Cisco and partner management software cannot inventory, monitor, and manage

nonqualified DIMMs. Cisco UCS Manager can inventory, monitor, and manage only DIMMs qualified by Cisco.

Failure Analysis of a Cisco UCS Server with Nonqualified Memory

This section provides the actual failure analysis done by a systems integrity engineering firm to analyze a returned

Cisco UCS server that used nonqualified DIMMs. The following images and results are excerpted from its findings.

Summary of results:

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Server failure was attributed to a DIMM that Cisco had not qualified. Its connector pins were bent.

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Two distinct differences between qualified DIMMs and nonqualified DIMMs contributed to the failure:

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The nonqualified DIMM was approximately 2 millimeters thicker than the qualified DIMM.

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The nonqualified DIMM used a thick hard-nickel plate over the copper with squared corner lands that

flared slightly upward over the edge of the PCA (burrs). Hard nickel will not yield during impact, in

contrast to the copper with thin nickel used on the DIMMs qualified by Cisco.

Supporting evidence can be seen in Figures 1 through 12.