PCI-E Connection between two servers

pci-express

I'd like to achieve PCI-E Gen3 X16 duplex speed for my server file transfers. I thought about this and asked myself why not.

I saw cable connecting PCI-E slot and a PCI-E riser card. So I believe there is already a cable exists to connect PCI-E slot to another PCI-E slot. Now I guess I need some kind of connection protocol to work with PCI-E.

Anyone has knowledge about this?

Best Answer

A PCI-e bus is not the same thing as a PCI-e device. There would have to be custom circuitry on both sides, most likely a PCI-e card that supports high-bandwidth interconnects.

The interconnect protocol most likely to be of use to you is Infiniband (IB), which can run at 4-lane speeds up to 40gbits/sec.

This is not cheap by any means, but for a point-to-point solution, you can't beat it.

Bandwidth:

legacy PCIe 1.x - 250MB/s per lane (16x == 16 lanes)
current PCIe 2.0 - 500MB/s per lane (thus 16x PCIe 2.0 is 8GB/s)
upcoming PCIe 3.0 - 1 GB/s per lane

Physical size (from Wiki):

The width of a PCIe connector is 8.8 mm, while the height is 11.25 mm, and the length is variable. The 'minor' half of the connector is 11.65 mm in length and contains 22 pins, while the length of the 'major' half is variable. The thickness of the card going into the connector is 1.8 mm.

Lanes | Pins Total | Pins in 'major' half | Total Length | Length of 'major' half 
------+------------+----------------------+--------------+-----------------------
x1    |  36        |  14                  | 25 mm        |  7.65 mm 
x4    |  64        |  42                  | 39 mm        | 21.65 mm 
x8    |  98        |  76                  | 56 mm        | 38.65 mm 
x16   | 164        | 142                  | 89 mm        | 71.65 mm

PCI Express x4 network card into PCI-Express x16 slot

Yes, it works just fine, obviously it's only work at x4 speed (8Gbps).

I would check whether the x16 slot can handle the power load of the x4 adapter, it depends on the adapter but I've seen some quite high power draw adapters using x4 electricals without an external power connector such as those you see in higher-end video cards. In some cases system-board manufacturers expect that adapters going into x16 slots will usually use external power connectors so they rate them with a slightly lower power draw capability from the board than from the lower-speed slots. This probably won't matter in your case but I wanted you to be aware.

Best Answer

Related Solutions

What’s the bandwidth and form factor for PCIe x1 x4 x8 and x16

Bandwidth:

Physical size (from Wiki):

PCI Express x4 network card into PCI-Express x16 slot

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