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Detritus Maximus
Asked: 2010-12-18 07:43:47 +0800 CST

What does "routing" mean in regard to pci express speeds / capabilities?

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This document for one of our servers says:

I/O Slots 4 PCIe x 8 (x4 routing), 1 PCIe x 16 (x8 routing)

What does the routing mean? Does it mean the card in the x8 slot can only run a x4? That is what I fear from reading this bit in the Wikipedia write up, yet it doesn't use the term "routing."

pci-express

1 Answers

  1. Best Answer

    Routed == usable.

    Your card in the x8 slot can only run at x4.

    The slots can physically accept x8 and x16 width cards but those cards will only operate at x4 and x8 speeds. respectively. (Actually the x16 can accept x1 x2 x4 as well.)

    This process is called "down-shifting." If you search for "pci express down-shifting" you find out about it.

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