Friday, August 4th 2017
AMD X399 Platform Lacks NVMe RAID Booting Support
AMD's connectivity-rich Ryzen Threadripper HEDT platform may have an Achilles's heel after all, with reports emerging that it lacks support for booting from NVMe RAID. You can still have bootable NVMe RAID volumes using NVMe RAID HBAs installed as PCI-Express add-on cards. Threadripper processors feature 64-lane PCI-Express gen 3.0 root complexes, which allow you to run at least two graphics cards at full x16 bandwidth, and drop in other bandwidth-hungry devices such as multiple PCI-Express NVMe SSDs. Unfortunately for those planning on striping multiple NVMe SSDs in RAID; the platform lacks NVMe RAID booting support. You should still be able to build soft-RAID arrays striping multiple NVMe SSDs, just not boot from them. Pro-sumers will still be able to dump their heavy data-sets onto such soft-arrays. This limitation is probably due to PCI-Express lanes emerging from different dies on the Threadripper MCM, which could present problems to the system BIOS to boot from.
Ryzen Threadripper is a multi-chip module (MCM) of two 8-core "Summit Ridge" dies. Each 14 nm "Summit Ridge" die features 32 PCI-Express lanes. On a socket AM4 machine, 4 of those 32 lanes are used as chipset-bus, leaving 28 for the rest of the machine. 16 of those head to up to two PEG (PCI-Express Graphics) ports (either one x16 or two x8 slots); and the remaining 12 lanes are spread among M.2 slots, and other onboard devices. On a Threadripper MCM, one of the two "Summit Ridge" dies has chipset-bus access; 16 lanes from each die head to PEG (a total of four PEG ports, either as two x16 or four x8 slots); while the remaining are general purpose; driving high-bandwidth devices such as USB 3.1 controllers, 10 GbE interfaces, and several M.2 and U.2 ports.
There is always the likelihood of two M.2/U.2 ports being wired to different "Summit Ridge" dies; which could pose issues in getting RAID to work reliably, which is probably the reason why NVMe RAID booting won't work. The X399 chipset, however, does support RAID on the SATA ports it puts out. Up to four SATA 6 Gb/s ports on a socket TR4 motherboard can be wired directly to the processor, as each "Summit Ridge" puts out two ports. This presents its own set of RAID issues. The general rule of the thumb here is that you'll be able to create bootable RAID arrays only between disks connected to the same exact SATA controller. By default, you have three controllers - one from each of the two "Summit Ridge" dies, and one integrated into the X399 chipset. The platform supports up to 10 ports. You will hence be able to boot from SATA RAID arrays, provided they're built up from the same controller; however, booting from NVMe RAID arrays will not be possible.
Source:
Tom's Hardware
Ryzen Threadripper is a multi-chip module (MCM) of two 8-core "Summit Ridge" dies. Each 14 nm "Summit Ridge" die features 32 PCI-Express lanes. On a socket AM4 machine, 4 of those 32 lanes are used as chipset-bus, leaving 28 for the rest of the machine. 16 of those head to up to two PEG (PCI-Express Graphics) ports (either one x16 or two x8 slots); and the remaining 12 lanes are spread among M.2 slots, and other onboard devices. On a Threadripper MCM, one of the two "Summit Ridge" dies has chipset-bus access; 16 lanes from each die head to PEG (a total of four PEG ports, either as two x16 or four x8 slots); while the remaining are general purpose; driving high-bandwidth devices such as USB 3.1 controllers, 10 GbE interfaces, and several M.2 and U.2 ports.
75 Comments on AMD X399 Platform Lacks NVMe RAID Booting Support
So much speculation you added to this article.
You forgot this part from the Tom's Hardware article:
"We were also told that AMD is going to enable the feature, but there isn't a firm timeline. It's one thing to talk about booting from an array of speedy next-generation storage devices that can surpass 5,000MB/s with just two drives; it's another thing to actually deliver.
There is a small market for such a thing... and it is quite a surpise it cant. Intel can on x299, i believe even with 28 lane cpus too. ;)
RAID requires UEFI/BIOS support, as well as potentially a driver, but it seems like AMD hasn't had the time to do this as yet. Not saying it'll happen, but even the Z170 platform wasn't perfect from day one and only supports RAID-0.
You can still create storage RAID arrays using NVMe, and put all your programs and games and datasets on that. And just run Windows off a SATA array, or heck a single NVMe drive.
And it isn't like Intel's X299 RAID situation is any better. You can only boot from NVMe raid if you use Intel branded SSDs. You can't do anything other than RAID-0(so nothing redundant) unless you buy a special dongle to plug into the motherboard to enable those features(and I'm sure that dongle ain't going to be cheap).
Vroc is a different feature.
Still, seems odd that it's not working, but then I guess we gotta settle at some point.
go do your benches and you'll see, hardware RAID on consumer boards is just a feature sale when in reality if you really want RAID then go get a proper HBA. This is really a non-topic for AMD architecture when their CPUs perform better and at a lower price point than Intels beasts especially in prosumer markets.
Anyway get the fastest NVMe out there, sure it;s a PITA for existing users but like I said for reliability purposes, I'm told, you don;t raid your work machines, unless of course it's RAID 1, 5, 10 et al.
This is disappointing for me I have 3 512gb nvme drives I want to use.