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BladeSystem - General
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Mix DIMMs in BL490G6?

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Mix DIMMs in BL490G6?

I have BL490G6 with (6) 4GB DIMMs. Can I add (3) 8GB DIMMs?

The DDR3 memory tool breaks with this case, giving no answer.

Honored Contributor

Re: Mix DIMMs in BL490G6?

yes You can if these rules apply

DIMM slots that are white should be populated first
Do not mix Unbuffered memory (UDIMMs) with Registered memory (RDIMMs)
Do not install DIMMs if the corresponding processor is not installed
If only one processor is installed in a 2CPU system, only half of the DIMM slots are available
To maximize performance, balance the total memory capacity between all installed processors
It is not required, but it is recommended to load the channels similarly if possible
You can only have up to eight (8) ranks installed per channel
You can only install two quad-rank DIMMs per channel
You can only install two UDIMMs per channel; if available, the third slot in the channel must remain empty
Populate DIMMs from heaviest load (quad-rank) to lightest load (single-rank) within a channel
Heaviest load (DIMM with most ranks) within a channel goes furthest from the chipset
For memory mirroring mode, channel 3 must be unpopulated. Channels 1 and 2 are populated identically
For lock-step mode, channel 3 must be unpopulated. DIMMs in channels 1 and 2 will be installed in pairs. The paired slots will be 1,4; 2,5; 3;6 on a 3DPC system or 1,4; 2,5; on a 2DPC system
No mixing DIMM voltage; all DIMMs must be the same voltage
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Re: Mix DIMMs in BL490G6?

Good set of rules, all repeating the info from the ddr3 memory tool. However nothing about DIMM sizes, which is where the tool breaks.
Honored Contributor

Re: Mix DIMMs in BL490G6?

Hi c3,

You can use different size sticks in different slots:

"It is not required, but it is recommended to load the channels similarly if possible."

Check the quickspecs here:

and look for their specific example of:
"Standard memory plus optional memory (1 CPU model)"

which is similar to what you are trying to do.
Good luck!