I/O Expansion Options - IBM System x3950 X6 Product Manual

I/O expansion options

The server supports up to 22 PCIe slots plus two dedicated Mezzanine LOM slots (24 total) as follows:
In each of the two Storage Books (standard in all models): Two PCIe 3.0 x8 slots for supported

internal RAID controllers and SAS HBAs
In each of the two Primary I/O Books (standard in all models):

o Two PCIe 3.0 x16 slots (x16-wired), half length, full height, up to 75 W of power
o One PCIe 3.0 x16 (x8-wired), half length, full height, up to 75 W of power
o
One mezzanine LOM 2 (ML2) slot for network adapters with the new ML2 form factor (PCIe 3.0
x8)
Four optional I/O Books, each with three slots, all full height. Optional I/O Books are hot-swap

capable.
The following figure shows the Primary I/O Book with the air baffle raised to show the internals.
Figure 8. Primary I/O Book
Optional I/O Books can be either of:
Half-length I/O Book:

o Two PCIe 3.0 x8 slots (x8 wired)
o One PCIe 3.0 x16 slot (x16 wired)
Full-length I/O Book:

o
Two PCIe 3.0 x16 (x16 wired)
o
One PCIe 2.0 x8 slot (x4 wired)
IBM System x3950 X6 21