A nvme disk on the WWAN / M.2 key B slot?

Banana Pi Router design BPI-R4(MT7988)
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I have searched a lot on aliexpress for an adapter for the WWAN / m.2 key B slot, so i can use a nvme disk there. But found no adapters, most are B+M, i don’t think they fit in key B slot, or do they?

I want to build a RAID1 volume with the nvme and WWAN / key B slots. The dual mpcie slots are occupied by the wifi be1400 card. So only that slot left.

Any ideas guys?

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I did the same … 4 NVME Disks with 4TB each in the R4. It works fine! For the Key B slot I used a B+M to M adapter, and 2 mPCIe to m.2 M-key adapter. The device is in production now with 3 NVME Discs in Raid5 and one slow wifi card. In future I want to build a 2 lane mPCIe to m.2 adapter, as all adapters I found only feed one pcie lane to the disk. But right now ethernet speed is limited due to missing LRO / RSS patches, so faster disks are worthless.

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What adapter did you use on the key b slot?

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I think there may be more users interested in this, including myself.

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I don’t know exactly which adapter I ordered, but it looks like this: https://www.aliexpress.com/item/1005005218158216.html

For the 2 lane mPCIe adapter: I found a 1 lane adapter on oshwlab.com and started modifying it for the second lane. The schematic is finished, but I need to learn how to route high speed traces of equal length …

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So, the M part of the connector is actually out of the slot, right? I mean, not inserted. Because the slot is just key B, not B+ M like that adapter.

BTW, you can alwas check your orders on ali.

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The adapter has 2 cutouts, of which only the B cutout in the socket is useful. The other cutout does not cause any problems. In the picture I pulled the adapter out of the slot a little so you can see it better.

PXL_20250204_234944616
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I can’t see the Aliexpress orders because I often create new Aliexpress accounts to get new welcome offers, in this case 70% off :smiley:

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Thanks a lot for this. Will order it.

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Are you using a small 2242 SSD, or a regular 2280? I had to modify my heatsink to fit the adapter and SSD. In my production system, a small WIFI card sits in the B slot (with an adapter) so I could install the large SSDs on the bottom. I even put a thermal pad between the SSDs and the case so the SSDs get a little cooling right away.

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Normal nvme, 2280. Or maybe some 2242 2TB disk, probably from WD.

Edit, i do plan to use a fan, because on my tests, the fan+heatsink combo lowers temps by at least 15º!