Has Sequoia finally resolved the PCIE M.2 NVME mounting issues so many faced?

It's not like mine is a one-off case. The inconsistency in the drives mounting is a widely recognised and reported issue both with 2019 and 2023 Mac Pro's. I'm not spending a load of extra hours essentially being a tester on behalf of Apple - if they've had that long to sort the issue, my single report isn't going to change anything.

You may have two other possible options. I certainly would not be changing my working system just to find out things are still broken, the wipe & restore once more. If you have enough Free storage space on your internal macOS SSD, then create a new APFS volume next to your Ventura volume and install Sequoia to it with nothing no third party software or data installed except what is needed to work with the RAID & test it.

Or since most people don't purchase a large enough internal SSD when configuring their Macs especially since you are using a RAID which implies you are dealing with large amounts of data, the better option would be to install macOS Sequoia onto an external USB3 SSD. Then when a new update comes along, boot from that Sequoia installation & update it to the latest version & test. For a test drive, this external SSD would not need to be large or expensive....even a slow hard drive may be sufficient as long as the RAID issue is not related to the amount of data being transferred between the boot drive and the RAID.

You keep your working Ventura installation and wait until you feel Sequoia is now working properly with your RAID before you take the leap & actually upgrade the Ventura installation to Sequoia.

Anyone that depends on a stable & reliable system should have such system in place to test OS updates & upgrades before actually applying them to the main boot drive, although this is becoming more & more difficult especially once M-series Macs are involved, but for an Intel Mac this should not be a problem.

Yes and no. Seems 15.1 fixed the issue of intermittent successful booting with Raid-assembled NVMEs on multi-M2 card (mine are Sonnet x2 and x4 cards) mounted in the backplane 7,1 PCIe buss. BUT 15.2, which I upgraded to, degrades it back. And is no longer solid. I’ve just gone through the long process of returning to 14.7 because I could not get a 15.1 image.

I can confirm the issue still exists. Apple should provide an solution as soon as possible. Might be the next update.

This is the correct answer.

I'm the original poster from that macrumors post.

15.1 - stable.

15.2 - Breaks Raid drives mounting.

15.3 - ? Hesitant to waste hours of my time degrading again

I think the issue being discussed here in an issue where softRAID can not recognize drives, and AppleRAid has some trouble.

Problems with plain Disk Utility are likely caused by something else.

Readers have reported that drives that rely on Promise Drivers may need those drivers, or slightly different version, installed manually, as the version included in MacOS is stale.

Be sure to check with the card vendor for direct guidance on what Drivers might be needed for Sequoia.

OWC says they think its fixed.

consider that you may have a different or more complex problem.

Apple does not Act on what is Witten here -- you need to contact support or write them a note on product feedback page.

I have a 2023 Mac Pro, and updating to Sequoia has not resolved the internal PCIe random non-mounting on startup issue for me.

The issue was previously occurring for me on every other startup on both Monterey and Ventura, and if anything it's now worse on Sequoia - it took me about 10 startups this morning before the drives mounted. The issue has happened when using both OWC and Sonnet cards, so it's definitely still an issue with the computer rather than the cards.

To spend this much money on a supposedly top of the range Apple computer for it to not work properly (with the PCIe cards recommended in its own promo material!) is pretty atrocious. The PCIe buses are pretty much the only extra thing that the Mac Pro even has over Mac Studio, so at least have it working correctly.

Apple can not act on only your words, and they are not reading the words you write HERE on the User-to-User forums.

if you want resolution, you need to contact Apple support, work with them on obvious possible problems, and if not resolved, ask a specialist to contact you, and continue to work with an Apple support specialist.

Resolution is either solving the problem, or filing a formal, numbered, tracked, Bug Report. You need to provide them with enough information that they can un-ambiguously re-create the problem in a test system in their labs. Then they can instrument that system, determine what the issues might be, and move to resolve them.

I have address issue by removing Apple Raid from the equation. I am using two 2TB SSDs on a x2 Sonnet card without striping, and replaced my x4 Sonnet card with a HighPoint hardware RAID x4 card.

Noted that 15.3 is now available, but not interested in upgrade at this time to test. (Nothing listed in upgrade notes addressing this issue)

2025 and the issue is still going, Im using 2 externals ssd nvm2 drives on a mac mini m4pro, since space purchase is expensive nonsense.

My primary external is 1tb kingston drive where is all the main data, secondary is 2tb kingston working on time machine backuping all including my primary data disk, Sometimes on when wakeup disk disapear and troubles comes at the moment of savings files (I ussualy note this when i want to save a file).

I dont really shut down my mac often, but when I do, is common that the drives dont appear at first, sometimes y reboot and other times I open disk utility and there ther are, so I mount 1 and both magicaly mount.

This is really scary for me, cause all my data is in these disks, Im thinking in make an backup in another disk just in case...

You can easily send them a product feedback report in only a few minutes, without even mussing your hair:

Product Feedback - Apple

they read these, but make no promise to respond to you directly.

I'd like to know too, specifically for the MacPro 2019

This page is saying yes - https://eshop.macsales.com/blog/96473-macos-15-sequoia-2019-mac-pro/.