U.2 NVMe backplanes

TrueNAS General
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Hi all,

I’m trying to spec some hardware to replace a spinning rust TrueNAS Core system with U.2 NVMe drives and running TrueNAS Scale.

I know what drives I want, I know what HBA(s) I want, but I need a little advice on backplanes and enclosures.

I’m currently looking at an ZhenLoong 8 Bay 2.5-inch NVMe U.2 Hard SSD Hot Swappable Module Cage Gen4 32Gb Backplane SFF8654 installation Space of 2 DVD-ROM from Zhenloong on Aliexpress (sorry, can’t add URLs here), but I was concerned by the “32Gb backplane” tag. As far as i’m aware, 32Gb (Gbit/s? or Gbyte/s?) isn’t a huge amount for a backplane for 8 drives is it? But then since the drives are paired so that 8 drives get presented on 4 SFF8654 interfaces, is it 32Gb per interface?
Has anyone got one of these and can do some benckmarking? I primarily want IOPS from this setup, so was considering 2 HBAs such as Broadcom 9670W but if the backplane hamstrings the install then I may need to think again.

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When you joined the forum, you got a PM from @TrueNAS-Bot inviting you to take a new user tutorial. Find that PM, respond to it, and complete the tutorial–that will increase your user trust level and allow you to a variety of things, including posting links and images.

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Hi! To find out what I can do, say @truenas-bot display help.

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OK so the URL is https://www.aliexpress.com/item/1005008902570782.html?spm=a2g0o.productlist.main.2.5d37WYoCWYoClY&algo_pvid=7b06708e-2908-47d0-bcf5-cba5ef0e55ad&algo_exp_id=7b06708e-2908-47d0-bcf5-cba5ef0e55ad-1&pdp_ext_f={"order"%3A"-1"%2C"eval"%3A"1"}&pdp_npi=4%40dis!GBP!133.19!133.19!!!172.10!172.10!%4021010c9a17472212782236807e1699!12000047133463293!sea!UK!0!ABX&curPageLogUid=kH6FmP7CtOJZ&utparam-url=scene%3Asearch|query_from%3A

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With NVMe drives you just want PCIe lanes, or a PCIe switch, but NOT a HBA. Forget Tri-Mode.

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This. Stay away from the tri-mode adapters. In most cases, you are hindering performance. Not only that, but you are likely going to be cheaper in the end by just buying an NVME backplane.