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!

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Ok, just for confirmation, got the adapter and works with nvme disks. Around 680/690MB/s with hdparm -t, more than enough for me. I just want a backups NAS.

https://www.aliexpress.com/item/1005005218158216.html

The bad news, is that indeed, with a 2280 disk, the heatsink needs to be cut, even the fan needs to taken out for the disk to fit OR a 2242/2230 disk can be used and the adapter shortened by the dot lines. OR another kind of heatsink installed.

Another bad news, is that the second attachment hole in the R4, for the 2242 size, does not fit precisely in the adapter’s 2242 hole. But the bolt kind of fits in there. If not, some kind of tape can be used to lower the adapter.

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The WD-SN740 works nicely, but it does need a quirk.

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Please share the quirk.

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The adapter fits after I removed 2 of the aluminum fins. You can attach the adapter to the motherboard with one screw and the SSD to the adapter with another screw. The fan continues to rotate, barely, but it fits. You can see it spinning in my picture above, you don’t need to take it out.

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