I’m trying to connect a Micron 7500 PRO U.3 SSD inside a Dell Precision 7875 (with a Threadripper PRO 9955WX)
The first PCIe card I’ve tried is the Glotrends PU13. It didn’t work, the computer didn’t even recognize the SSD drive (the BIOS literally said that the PCIe slot was empty)
I returned it and bought a different one, an NFHK U.3 card (it says revision 5.0 printed in the PCB). This one at least is recognized by the BIOS (it says that a “Mass storage” device is plugged into the PCIe slot), but the computer completely freezes/hangs when booting from the SSD and I have to literally unplug it from the wall to recover it.
I’ve already returned it and I’m thinking of buying another card, this time from a chinese manufacturer called JEYI (although they don’t advertise it as U.3, they say it’s a U.2 card compatible with U.3 drives)
Does anyone have experience with U.3 drives and U.3 pcie cards? Are all of them the same crap? Basically a scam?
Is it better to just buy a U.2 pcie card and force the U.3 SSD drive into compatibility mode with U.2 hosts?
I have four Micron 7450 Pro U.3 SSD’s which I run in a Mdadm Raid0 in an Gen4x16 slot using bi-furcation (x4x4x4x4) originally tested on an Epyc 7642 with Asrock Romed8-2t .
I had a similar problem of trying to find a U.3 pcie card so I tried the Glotrends PU41 first, but found that had a few problems. First problem was the card was unable to work with all four SSD’s populated at the full Gen4 link speed. Only 2-3 of the 4 cards would be detected. Dropping the link speed to Gen3 would make all of the cards detected, but under load when testing with fio I started getting error and the IPMI interface showed pcie timing errors. I was finally able to track it down to the Micron cards can pull around 25W under full load which combined is more than the 75W that the passive PCI card could supply.
I ended up getting the JMT ADT-R37 PCIe5.0x16 to 4-Port U.2 as it has an additional 6+ power pin and that was able to negotiate and work with the Gen4 link speed with bi-furcation. I ran fio and that showed ~18-21GB/s iirc but that was against the mdadm raid0 array so a little less than theoretical, but good enough for what I needed.
I have not tried a single U.3 micron configuration, but I would not be surprised if they either have the same link speed negotiation or power draw issue. (might be why the card was detected but unable to boot).
No, they rely on the motherboard splitting the pci lanes for bifurcation. If you want to split the lanes on the card instead of the motherboard you would need to get a card with a PLX chip to split the lanes.
I’m coming to the conclusion that all of the cheap PCIe U.2/U.3 adapters are basically useless, a scam of sorts.
I have tested five different adapters in total. None of them work.
Here’s a summary:
PASSIVE CARDS (these cards do not have any chip in them, they are just passive and extremely cheap)
Glotrends PU13 x4 card (totally broken, not even recognized by the BIOS. It had many scratches in the surface, even though it came in a sealed and well protected box, so I suspect that those scratches were made during manufacturing or while packing it in the factory)
NFHK U.3 x4 card revision 5.0 (the SSD is recognized by the BIOS, but computer freezes at startup)
JEYI U.2 to PCIe 4.0 Adapter (x16 slot, black PCB, seems of decent quality, but computer still freezes at boot)
JEYI PCIe 5.0 to U.2 Converter (x16 slot, purple PCB, seems to be manufactured with higher quality than the rest, but the result is the same. Computer hangs and freezes at startup)
ACTIVE CARD
BTBcoin AC5929 Dual U.2 SSD to PCIE 4.0 x8 Adapter (x8 slot, this fraudulent card says it supports PCIe 4.0, but the clock buffer chip soldered in the card is a Pericom PI6C20400B, which only supports PCIe 3.0, and doesn’t meet PCIe 4.0 requirements. The result is the same, computer freezes and hangs at startup)
So, having exhausted all the cheap options, my next step will be to test the really expensive ones. Main problem is that the expensive ones don’t allow you to plug in directly the SSD, you must also buy cables that increase the cost a lot!
I’m currently looking for one of these two models:
If you are stepping up to more expensive models then the first one I would try is MicroSATA cables brand, as they make some of the best adapter things of this nature.
This does an x16 slot to two 8 lane outputs:
Then an 8 lane SlimSAS PCIE4.0 cable to dual U.2 connectors (full 4 lanes per SSD):
or an 8 lane cable to four 2 lane U.3 connectors (so 2 lanes or half bandwidth to each SSD):
Or finally an 8 lane cable to eight 1 lane U.3 connectors:
edit:
Or one of their PCIE x4 to single U.3 adapter cards:
I’m saving them for reference, I’m guessing I’ll probably end up buying some of that gear.
However, before that I’m going to try one last cheap option that could maybe work, to finally exhaust ALL the possible cheap options in existence in this world.
My final cheap option is a cable made by a chinese company called XIWAI
It should theoretically work in my Precision tower, because I’ve inspected the motherboard and it does have two empty MCIO 4x ports.
I’m crossing my fingers and holding my breath until it arrives, maybe a miracle can occur! Stranger things have happened!
Why would they be a scam? They’re just a short cable runs (traces in this case) with a U.2 socket?
Where you will fall down with them is if you’re pushing the power budget for the slot. Keep away from the 75 watt ceiling of the slot or hook up the supplementary power cable.
I am using three of similar cards to the “JEYI U.2 to PCIe 4.0 Adapter” you mentioned, as well as two other PCIe to U.2 cards with a mixture of Intel P4510 8TB and Optane 905p U.2, and Micron 7450 Pro U.3 8TB.
I was running 4x Micron 7450 Pro U.3 8TB in an array, and yes, those ones could be temperamental and most definitely want the sup-power connected.
I have since had a few changes in the rack, and the Microns have been split up throughout the different servers and are connected via the genuine Intel M.2 to U.2 cables that come in the box with the Optane drives.
My first suggestion to you would be to put 2x Micron 7450 per card, per slot, and try that. You have the spare cards anyway, so that is a zero $$$ easy thing to test with.
You won’t need to bother with the extra power lead, just stagger the 7450’s in the cards so that they breathe a bit better if using 2x U.3 per card - think different offsets so that the NVMes aren’t back to back.
Maintain the PCIe 4x4x4x4 split that you would already have set up in BIOS currently for each slot.
Try that, as they do work here on Threadripper Pro motherboards I have with a mixture of 3955WX up to 5975WX(s).
Actually, you’re completely right. Out of curiosity I’ve tried the two JEYI adapters that I have with my Micron drive in a few other computers (three regular desktops with budgdet Asrock and MSI boards, and a server with a gigabyte MC12-LE0 board)
The results? It works fine in ALL of them. The SSD is correctly recognized and boots Windows perfectly without errors!
It appears that is actually the BIOS of my Dell Precision that is either buggy and/or deliberately castrated to force you into buying Dell-branded PCIe carriers (like the Dell Ultraspeed Duo or Ultraspeed Quad cards)
The stupidest thing of all this is that Dell only sells carrier cards for M.2 SSDs, and doesn’t have anything for U.2 SSDs
They simply block the use of third party cards without even offering an option themselves!! WHAT A GREAT IDEA, DELL!!
Ok, I have received the XIWAI cable, and I have connected it to one of the MCIO 4x connectors in the motherboard.
The result is exactly the same. It freezes/hangs at boot (at the UEFI dell logo)
The funny thing is that I can enter the BIOS and the SSD is perfectly recognized, it even detects the brand and model and everything seems to be OK.
But it will never boot. It’s a stupid bug or a deliberate restriction imposed by Dell.
Anyway, the lesson is abundantly clear: STAY AWAY FROM THE DELL PRECISION 7875 ! IT’S NOT COMPATIBLE WITH U.2/U.3 DRIVES, NO MATTER WHAT KIND OF METHOD YOU USE!!
Serves me well for being such an idiot and buying a Dell computer. I should have known better
