Mezz2 needs a second CPU installed in order to be used?

[SYSTEM]

Mezz2 needs a second CPU installed in order to be used on BL460G8 / BL420G8?
As far as I know neither IBM nor DELL must have two CPUs in order to use the second mezz slot.

[SYSTEM]

Information taken from quickspec for BL460c G8

Step 2: Choose Required Options (one of the following from each list unless otherwise noted)
HP Processors Core Processor Option Kits
NOTE: The BL460c Gen8 supports one or two processors.
NOTE: All configure-to-order processor kits (i.e. xxxxxx-L21) contain one (1) processor.
NOTE: If two processors are desired, select one xxxxxx-L21 here in Step 2 and one xxxxxx-B21 in Step 3.
NOTE: The BL460c Gen8 includes two I/O mezzanine expansion slots. A processor must be installed in processor slot 1 for access to the first mezzanine expansion slot (expansion slot 1). A processor must be installed in processor slot 2 for access to the second mezzanine expansion slot (expansion slot 2).
NOTE: All processors within the server must be identical.
NOTE: All processors support Intel Hyper-Threading and Intel Turbo Boost Technologies except the E5-2603 and E5-2609.
NOTE: The letter "L" following the model number indicates denotes lower wattage.
NOTE: The processor model as well as the memory configuration determines the maximum speed memory can operate. Please see the see the "Memory" section later in this document.
NOTE: The Intel Xeon E5-2620 processor does not support DIMMs at 1.35V. Using the HP RBSU, 1.35V DIMMs can be changed to operate at 1.5V.

[SYSTEM]

The Sandy Bridge architecture puts the PCIe controller inside the CPU, but nothing prevents a system designer to route 2 PCIe slots to a single CPU.

HP do that in DL servers for example.

It appears that Dell and IBM haven chosen that way for their blade servers as well (and I assume not use the PCIe lanes off the second CPU), while we have made the opposite choice. I guess that could give a performance advantage in fully-loaded configs.

[carrot]

高端的东西，麦子卡！！！