16x PCIe Quad M.2 Adapters Without Need for Bifurcation?

[Zarathustra[H]]

Hey all,

So, my server is based around an aging Supermicro X9DRI-F. I haven't upgraded yet, as I don't feel like spending the money to re-buy 256GB RAM in DDR4.

The plan was to start moving over to NVMe drives for some of the caching and other needed fast storage devices, as the old SATA stuff is getting old and slow. I had read good things about those Dell Quad adapters, but they apparently depend on PCIe bifurcation being supported by the motherboard.

As a first step, I bought a couple of 280GB 900p U.2 Optane drives and a Supermicro AOC-SLG3-2E4R U.2 adapter which also requires bifurcation. I could not get this to work no matter what I did. The manual and bios suggests this board supports bifurcation on all 6 PCIe slots. (3 16x, 3 8x). Unfortunately it does not work as advertised. Turning bifurcation on on the slot does not appear to have any effect, and only the first device is ever detected by the system.

After spending an evening trying to remember how to create a bootable DOS USB stick, upgrading the bios and testing all of the slots, I decided to hit up google, and it turns out other have the same issue with this motherboard. Oh well.

I am returning the AOC-SLG3-2E4R and picking up the R less version (AOC-SLG3-2E4) which has a PLX chip to avoid the bifurcation requirement. Hopefully this will allow me to use the two Optanes in an 8x slot.

The question is, what - then - do I do for the remainder of my storage needs. The aforementioned quad Dell requires working bifurcation. I apparently can't trust that what is on my motherboard will work

I have done some googling, and came up with this thing on Amazon by a company I have never heard of named Adwits. It looks likre while it may have a 16x connector, it only uses 8x bandwidth shared over 4 devices, which is a little lame..

At least judging by this:

I would much prefer a non-blocking solution.

1.) Does anyone have any experience with it? Is it any good?

2.) Are there any other options that work without bifurcation I should be aware of?

Appreciate any suggestions.

 

[cdabc123]

Ive ran devices that require bifurcation on some pretty ancient hardware. Notably a old dual g34 Opteron build. Ive had issue with a dual lga 1366 board and a dual 2011 board. Do the Dell boards play nice on any modern rigs you might have?

 

[Zarathustra[H]]

Ive ran devices that require bifurcation on some pretty ancient hardware. Notably a old dual g34 Opteron build. Ive had issue with a dual lga 1366 board and a dual 2011 board. Do the Dell boards play nice on any modern rigs you might have?

I don't have any of the dell boards yet. I decided to test with the little 8x to two U.2 port Supermicro board. My assumption was that if it did not play nice with that board, it probably wouldn't play nice with any other devices requiring bifurcation either. Is that a bad assumption?

 

[Zarathustra[H]]

I also found this one. It claims to have a PLX 8747 chip which should be up to th etask of providing non-blocking bandwidth to four 4x m.2 drives.

It's a little pricy, but I guess my options are limited at this point if the X9DRI-F won't do bifurcation properly.

 

[cdabc123]

I don't have any of the dell boards yet. I decided to test with the little 8x to two U.2 port Supermicro board. My assumption was that if it did not play nice with that board, it probably wouldn't play nice with any other devices requiring bifurcation either. Is that a bad assumption?

A good portion of my experience with pcie bifurcation was on the older style of pcie sdds with multiple modules as well as some other pcie devices and I found it to be very temperamental: dependent on the device, motherboard, as well as specific pcie lane as well.

Temperamental devices and niche dell products have been synonymous for me.

Lookin into it abit the supermicro hbas you are looking it ?appears? to be limited to spacific boards, which is in contrast to what im used to seeing with supermicro hardware. Is it possible those require to be in a spacific pcie slot to work. Ive had boards with what was essentially a raid controler/pcie lane combined to be used with a spacific expansion card.

 

[Zarathustra[H]]

A good portion of my experience with pcie bifurcation was on the older style of pcie sdds with multiple modules as well as some other pcie devices and I found it to be very temperamental: dependent on the device, motherboard, as well as specific pcie lane as well.

Temperamental devices and niche dell products have been synonymous for me.

Hmm. Interesting. So you are saying that the temperamental nature of these things might mean that it might work with the Dell units even if it dodn't work with the supermicro card I tested. Interesting. I assumed PCIe bifurcation spec was PCIe bifurcation spec, and it was all or nothing.

I wish I could test one before buying everything

Lookin into it abit the supermicro hbas you are looking it ?appears? to be limited to spacific boards, which is in contrast to what im used to seeing with supermicro hardware. Is it possible those require to be in a spacific pcie slot to work. Ive had boards with what was essentially a raid controler/pcie lane combined to be used with a spacific expansion card.

Yeah, I read that in th emanual for the thing too. They specifically say it is for their X10 gen of boards. When I read that I assumed these were just the configurations they had validated, but that it should work on any system with bifurcation. Maybe that was an incorrect assumption.

Thanks for the info!

 

[cdabc123]

Hmm. Interesting. So you are saying that the temperamental nature of these things might mean that it might work with the Dell units even if it dodn't work with the supermicro card I tested. Interesting. I assumed PCIe bifurcation spec was PCIe bifurcation spec, and it was all or nothing.

I wish I could test one before buying everything



Yeah, I read that in th emanual for the thing too. They specifically say it is for their X10 gen of boards. When I read that I assumed these were just the configurations they had validated, but that it should work on any system with bifurcation. Maybe that was an incorrect assumption.

Thanks for the info!

Generally when supermicro says stuff it's not just a blanket statement. I would assume that's the issue running that particular adapter.

I dont believe 4 of those Dell adapters would work. For no particular reason it just sounds like alot of components would be unhappy with a config like that.

You might have better luck with one of the Chineseum cards with a common dedicated chip for the pcie routing. I think finding any motherboard that works with 4 of those cards will be temperamental to setup.