Sorry to revive this thread, but what cable did you use to connect the NVMe switch to the backplane? @mattventura
Broadcom 9400 - Can't get it to see NVMe drives on a backplane
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It worked perfectly fine with various SFF-8643 to 8643 cables (SMC, Asus, others). I'm currently using 4x CBL-SAST-0532 which seems to be the appropriate length for the rear backplane in an 847 (50cm).
I also bought a few AOC-SLG3-2E4 cards which have full working hotplug support. Couldn't get drive locate/fail LEDs to work with it, but fortunately the drives I use keep the activity light on by default, so powering off the drive will turn off the LED so you can see which drive you need to pull. Only having 2 ports is unfortunate, but at least it won't bottleneck.
Does the AOC-SLG3-2E4 need the special SMC cables? or will any miniSAS 8643-8643 work
Should work with any. Supermicro sells special "NVMe" SFF-8643 cables, but I believe the only difference is that they're certified to work for NVMe purposes.
And the cable ends are white to match the white back-plane connectors on SM nvme 8643 connectors!
thanks. I'm working with an X11 board that doesn't have bifurcation and needed this. Thanks.
Also an owner of a BPN-SAS3-826EL1-N4. With a basic plx switch card, any regular SFF-8643 will work *depending on length*. The overall length of the system threw me for a bit and required most testing. I almost wish the nvme slots were flipped to the other side of the backplane such that it's closer to the pcie slots of the motherboard and wouldn't have to route around the case fans. My first attempts with a 75 cm (nominal 78cm) cable from the pcie slot to the #1 slot of the backplane didn't work with a direct attach pcie card (X10DRH). Second attempt with a switch card made it work, but only the #1 nvme slot as the other slots (2-4) were still too far. Moving to a 55 cm cable made nvme slots 2-4 work.
It looks like the -N4 backplane itself is guilty of significant loss of (PCIe) signal dB; draining so much signal budget that a measly +20cm of cable did you in. I'll bet a cheap-ass 100+cm 8643-8639 cable from (any mobo slot) slot-adapter, or switch card, directly to U.2 drive will be A-OK.
For ref, my experiment 2yrs ago [Link]
Hi I have Broadcom 94008i, and I'm trying to figure out how to use nvme drives with it and what potential backplanes are compatible?
ok well Im asking as the card apparently supports hdds and nvmes but not much info on how to do it
1. Buy some overpriced proprietary cables (be sure to buy the correct one, since there's different pinouts)
2. Plug it into the backplane or bare drives
Also, with the 16i, there's at least some use case - if you really need 2 NVMe drives and a SAS HBA in one PCIe slot, it fills that niche. With the 8i, it's just a switch/retimer but worse. The only real advantage it has is that it will allow NVMe hotplugging no matter how bad your BIOS is.