1333MHz memory feature and power on 360 G6

[DerekS_1]

I have a G6 server with 12GB memory, which has 6x 2GB DIMMs. We have other servers with 36GB that have 6x 2GB and 6x 4GB DIMMs.

I noticed if I turn the BIOS feature on to use 1333MHz memory bus speed when 2 DIMMS per channel are present that according to the power meter consumption goes up 10W.

This happens on servers WITHOUT a second DIMM. I can understand the power increase on servers with 2 DIMMs per channel, but I'm baffled on the single DIMM servers. The servers with two DIMMs per channel show the same power increase, which I would expect.

Why would power usage increase when the setting should theoretically make no changes to the system?