Mezzanine Slot 2 in Gen8 blades need 2nd processor?

[chuckk281]

Chielsin had a Gen8 question:

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Anyone know why in order to add mezzanine card in slot 2, we must add 2nd proc in BL460c Gen8?

I think we don’t need one for BL460c G7.

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The info:

From Alexander:

This is because Gen8 CPUs’ architecture: the PCIe controller is embedded in the CPU.

And a detailed reply from Shigeru:

You need 2nd cpu when you configure a mezzanine card in slot 2. The reason is that the E5-2600 family provides PCIe Gen3 control up to 40 lanes, and the 1st cpu on BL460c Gen8 uses it 8 lanes for FlexibleLOM, 8 lanes for P220i and 16 lanes for mezzanine 1, therefore, there is no room for mezzanine 2 (PCIe Gen8 16 lanes) on 1st cpu. The 2nd cpu controls mezzanine 2.

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