I was searching through the internet to find PCI Express card edge connector footprints / technical drawings / pin spacing / layout of the module cards that you stick in these connectors you can find on a modern PC/server motherboard.

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I wasn't able to find anything so I thought I could maybe ask here? I found some for Altium Designer which I don't have access to and also I am using (Autodesk) Eagle.

If you are wondering, I wanted to create a PCIe 3.0 x8 card that could hold two M.2 NVME SSDs since I could not find this anywhere either. Everyone only sells the type that holds one NVME (PCIe) and one SATA SSD. This is not what I need.

M.2 NVME interface is basically just a PCIe x4 interface, in another form factor. Therefore I don't see a problem with making a x8 standard card for PCs/servers that could hold two of those and properly route their interfaces.

Can anyone help? Thank you!

  • \$\begingroup\$ For more details, the search term you need is "PCI Express Card Electromechanical Specification". \$\endgroup\$ Commented Jul 13, 2019 at 20:02
  • 1
    \$\begingroup\$ Searching for "pcie dual nvme adapter" on Google should give you a few results and plenty of leads. \$\endgroup\$ Commented Jul 13, 2019 at 20:05
  • \$\begingroup\$ If you look at the drawing for a PCIe connector it will also have the drawing for the mating card edge. See for example part 10025026-10003 from amphenol \$\endgroup\$
    – Keegan Jay
    Commented Jul 14, 2020 at 21:20

1 Answer 1


The official PCIe spec from PCI-SIG has this information. It’s downloadable from the PCI-SIG site for a fee, it’s free download for PCI-SIG members. Link: https://pcisig.com/specifications

By the way, Supermicro lists that kind of adapter (half-high to 2x NVMe.) Here it is on Amazon: https://www.amazon.com/Supermicro-AOC-SLG3-2M2-PCIe-Add-Card/dp/B071S3ZY8P

Check also ASUS, AIC and Funtin. These are ‘passive’ adapters that rely on the host to bifurcate the PCIe lanes - which means newer motherboards only with appropriate BIOS support (intel x299; AMD x399, Epyc, etc).

Amfeltec has an active adapter that can hold up to 4x M.2 in a half-high slot. It includes a switch and it’s rather expensive. It would literally be cheaper to get a different motherboard and use lane bifurcation.

If you can live with a full-height card there are more choices. The ASUS Hyper16 card, which takes 4x NVMe seems to be the most cost-effective. ASRock also has one.

  • \$\begingroup\$ The OP should be aware that some of those cards have 40 mm fans which might be too whiny for some use cases. \$\endgroup\$ Commented Jul 13, 2019 at 20:27
  • \$\begingroup\$ There’s a switch on the ASUS Hyper16 to turn the fan on or off. \$\endgroup\$ Commented Jul 13, 2019 at 20:30

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