Am I crazy for considering A-key to M-key m.2 adapter for Dell 7050 micro?

AveryFreeman

consummate homelabber
Mar 17, 2017
356
44
28
41
Near Seattle
averyfreeman.com
Hey,

So this is what I'm talking about: https://smile.amazon.com/Sintech-NGFF-NVME-WiFi-Cable/dp/B07DZF1W55/

I know x1 PCIe lanes is lame compared to x4, but hear me out: I want to build a cluster out of 5 Dell 7050 micros I have, I got a bunch of their motherboards for $10 each during the pandemic and have been slowly piecing them together as I have the resources since.

Fast forward to today, and I'm about to start putting them in a 4U hardcase rack sideways with 3x120mm fans blowing on them, so something like a card with a ribbon cable would work fine - I'm leaving the tops off the cases because of their thermal "design", ahem, in fact, the only reason I'm using the bottom of the cases is because of their proprietary CPU heatsink retention system, but I digress...

The thing about any of these micro computers is they're light on upgrade options. I could use the x4 slot for NVMe like they're intended, but I was thinking of getting a PCIe adapter and running RDMA-compatible 10GbE cards like Chelsio T520-CR, or something from Broadcom or Marvell that are in the ESXi HCL.

Actually, now that I think about it, 10GbE is essentially 1250MB/s max (via math, not reality) so that is actually closer to x1 PCIe 3.0 lane, 985MB/s, than an m.2 NVMe, which can get upwards of 3,500MB/s sequential. So maybe using the wifi slot (m.2 x1 E-key or A+E key) would make more sense for the storage networking infra than using the NVMe slot.

But the point was, I'm never going to use this WiFi slot for WiFi, I'd like to use it for either a 10GbE card or x4 NVMe. Has anyone tried one of these A+E-key to M-key adapters? I imagine they're pretty obscure...

I was just thinking of using the WiFi slot for NVMe instead of the NVMe slot since x1 is only 1/4 of x4, while the 10GbE cards are x8, so x1 is a much more dramatic reduction, but then when considering the throughput of an actual 10GbE card... Why do they need to be x8 again? Duplex?

Ok this is long and rambling, but if you were me, what would you do? Use the x4 slot for an x8 card, and the x1 slot for an x4 NVMe, or use the NVMe slot for it's intended purpose, and use x1 slot for 10GbE?
 

PD_ZFS-User

Member
Jul 13, 2018
31
10
8
I don’t think you‘re crazy. I’ve thought about trying to do something similar with an HP t740 to create a mini all in one storage and hypervisor server. I’m still researching the required adapter and whether I could fit it onto the board. I’ll leave you a couple of links. The first is a recent video from a Danish youtuber (in English) having some success with the same idea on a Lenovo M93p.

To give you a starting idea of what’s available, here’s a US company (that I have no experience with) that sells many different peripheral cards that use a mini pcie slot and also cards for other slots such as m.2. Hopefully you can find local resellers for these products. Innodisk EMPP-0201 mPCIe to Half mPCIe & USB Module 0C to 70

Best of luck with your search and I hope others will share their ideas and any working solutions.

PD
 

MBastian

Active Member
Jul 17, 2016
183
50
28
Düsseldorf, Germany
I would make sure your NIC and nvme disk actually supports x1. The NIC you mentioned needs at least a x4 link according to the official documentation. Running a 10Gbit NIC on x1 PCI 3.x link would theoretically allow it to reach approx 7.7 Gbit/s full duplex.
What is more important to you? Local disk or networking speed?
 

UhClem

Active Member
Jun 26, 2012
273
134
43
NH, USA
Crazy?? Not at all ...
You want crazy?
How about a ConnectX-3 40GbE (@ 3.5 GB/s max) *AND* an x4 M.2 (@ full 3.5GB/s) ??
[and you don't even mess with that wifi)

In your x4 M.2 slot goes this (~$20):
RiserCable.jpg
In that guy's x4 slot goes this (~$50 [uses ASM2812 switch]):
SwitchCard.jpg
In one M.2 goes an x4 NVMe SSD; in the other goes this (~$2-4):
M2-to-x4.jpg
In that (open-ended) x4 slot goes the ConnectX-3.

Crazy!! (like a fox? :))