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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!


marked as duplicate by Tom Carpenter, brhans, RoyC, JYelton, Finbarr Jul 26 at 15:52

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • \$\begingroup\$ For more details, the search term you need is "PCI Express Card Electromechanical Specification". \$\endgroup\$ – Tom Carpenter Jul 13 at 20:02
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    \$\begingroup\$ Searching for "pcie dual nvme adapter" on Google should give you a few results and plenty of leads. \$\endgroup\$ – Andrew Morton Jul 13 at 20:05

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\$ – Andrew Morton Jul 13 at 20:27
  • \$\begingroup\$ There’s a switch on the ASUS Hyper16 to turn the fan on or off. \$\endgroup\$ – hacktastical Jul 13 at 20:30

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