Which M.2 Interface for SSD?

[Fun Guy]

Just read up a little bit on M.2. I am building a new machine and looking at anything that will make it a little faster, since I usually run my machines for 5 years or more.

At first I thought that M.2 was an interface, but now I see it is just a form factor, with the interface being SATA, PCI-e, etc.

My question is, which interface is the best/fastest for an M.2 SSD? And the second question (of course) is which M.2 SSD should I get?

(FYI, I have yet to get my motherboard, so I will be taking this into account when getting one. At this point I am looking at Micro ATX Z97 boards.)

 

[ShintaiDK]

M.2 on the mobo is standard. Essentially a SATA Express that contains SATA port and PCie x4. You can plug in SSDs and Wifi cards etc in that.

The only thing that matters is the actual SSD. Almost all SSDs today are legacy SATA based and will give you a max of 600MB/sec. The best possible SSD is NVME based instead of SATA. But make sure the mobos BIOS actually support it. Samsung got one of these SSDs.
http://www.anandtech.com/show/8979/samsung-sm951-512-gb-review

And its pricy, roughly twice the cost of a SATA6 M2 SSD. Plus its close to, if not impossible to get your hands on.
http://geizhals.eu/samsung-ssd-sm95...e&hloc=at&hloc=de&hloc=pl&hloc=uk&hloc=eu&v=e

There is an AHCI version tho. Still double the price but its possible to get one:
http://geizhals.eu/samsung-ssd-sm951-512gb-mzhpv512hdgl-00000-a1215618.html

Tbh I doubt you could tell the difference the next 5 years between a SATA6 SSD and a NVME SSD unless you use a benchmark tool.

 

[freeskier93]

M.2 on the mobo is standard. Essentially a SATA Express that contains SATA port and PCie x4. You can plug in SSDs and Wifi cards etc in that.

The only thing that matters is the actual SSD. Almost all SSDs today are legacy SATA based and will give you a max of 600MB/sec. The best possible SSD is NVME based instead of SATA. But make sure the mobos BIOS actually support it. Samsung got one of these SSDs.
http://www.anandtech.com/show/8979/samsung-sm951-512-gb-review

And its pricy, roughly twice the cost of a SATA6 M2 SSD. Plus its close to, if not impossible to get your hands on.
http://geizhals.eu/samsung-ssd-sm95...e&hloc=at&hloc=de&hloc=pl&hloc=uk&hloc=eu&v=e

There is an AHCI version tho. Still double the price but its possible to get one:
http://geizhals.eu/samsung-ssd-sm951-512gb-mzhpv512hdgl-00000-a1215618.html

Tbh I doubt you could tell the difference the next 5 years between a SATA6 SSD and a NVME SSD unless you use a benchmark tool.

NVMe is a protocol like AHCI, not an actual interface like SATA/Sata Express/PCIe. The interface dictates theoretical max transfer speeds and the protocol will play a role in real world transfer speeds.

As noted by the OP M.2 is just a form factor, and it's really freakin' confusing right now. There are 3 common interfaces it uses; SATA III (6 Gb/s), PCIe x2, and PCIe x4. To make it even more confusing the PCIe interface can be either 2.0 or 3.0 and you'll have a REAL fun time trying to figure out what motherboards support what. For example my Asus board has an M.2 connector and specs are super vague. All they say is M.2 Socket 3 and that it supports 10 Gb/s. Best I can figure out this is PCIe 2.0 x2 and they are interchanging GT/s and Gb/s (PCIe 2.0 is 5 GT/s or 4 Gb/s per lane so 2 lanes is 10 GT/s or 8 Gb/s).

Now you also have the choice of AHCI or NVMe. NVMe will yield better real world transfer rates compared to AHCI. All of Asus' Intel 9 series motherboards support NVMe, I don't know if anyone else does yet.

Currently the fastest you can get right now is PCIe 3.0 x4 using NVMe. Samsung is the only one I know of that has an PCIe 3.0 x4 NVMe M.2 SSD.

http://www.anandtech.com/show/8865/samsung-launches-sm951-m2-pcie-30-x4-ssd-for-oemssis

 

[R0H1T]

NVMe is a protocol like AHCI, not an actual interface like SATA/Sata Express/PCIe. The interface dictates theoretical max transfer speeds and the protocol will play a role in real world transfer speeds.

As noted by the OP M.2 is just a form factor, and it's really freakin' confusing right now. There are 3 common interfaces it uses; SATA III (6 Gb/s), PCIe x2, and PCIe x4. To make it even more confusing the PCIe interface can be either 2.0 or 3.0 and you'll have a REAL fun time trying to figure out what motherboards support what. For example my Asus board has an M.2 connector and specs are super vague. All they say is M.2 Socket 3 and that it supports 10 Gb/s. Best I can figure out this is PCIe 2.0 x2 and they are interchanging GT/s and Gb/s (PCIe 2.0 is 5 GT/s or 4 Gb/s per lane so 2 lanes is 10 GT/s or 8 Gb/s).

Now you also have the choice of AHCI or NVMe. NVMe will yield better real world transfer rates compared to AHCI. All of Asus' Intel 9 series motherboards support NVMe, I don't know if anyone else does yet.

Currently the fastest you can get right now is PCIe 3.0 x4 using NVMe. Samsung is the only one I know of that has an PCIe 3.0 x4 NVMe M.2 SSD.

http://www.anandtech.com/show/8865/samsung-launches-sm951-m2-pcie-30-x4-ssd-for-oemssis

No it's not, Ultra M.2 (32Gbps) is what you wanna get, anything less is basically meh & achievable via software RAID through SATA III.

MSI, ASROCK, Gigabyte et al, in fact every major mobo maker now supports NVMe "drives" through a BIOS update

 

[bradly1101]

I have read in forums here and elsewhere that M.2 SSD's get very hot and apparently aren't easy to cool since they are mostly mounted right next to the motherboard. There's an Asus X99 board that mounts it vertically in the path of the front fans, which would be better.

But the best setup I think right now is (if your wallet is up to paying $1/GB) using that M.2 slot with an adapter to a 2.5" Intel 750 NVMe SSD (if you can find the connector or get the PCIe version if you have room).

 

[VirtualLarry]

MSI, ASROCK, Gigabyte et al, in fact every major mobo maker now supports NVMe driver through a BIOS update

But does Windows 7? Where's the freakin' NVMe driver, Microsoft!!??

 

[bradly1101]

But does Windows 7? Where's the freakin' NVMe driver, Microsoft!!??

Driver via the BIOS? The DRIVER is built into Win 8, and just needs to be downloaded and pointed to during a Win 7 install.

 

[phillyman36]

Who are the drives better suited for? On the reviews I look at there are all these benchmark graphs showing how much faster it is but when you get to the real world performance there doesn't seem to be much difference. Would this make a significant difference in say using handbrake, makemkv, clownbd in taking my blu ray collection turning it into an mkv container? It would probably copy faster to my nas i guess.

 

[Hellhammer]

No it's not, Ultra M.2 (32Gbps) is what you wanna get, anything less is basically meh & achievable via software RAID through SATA III.

"Ultra M.2" is pure marketing. PCIe 3.0 is 8Gbps (i.e. 1GB/s) per lane, so PCIe 3.0 x4 is 32Gbps.

 

[larryccf]

whatever board you go with, you should make sure the M.2 socket is PCIe 3.0 x4 (4 lanes). My Asus Z97m-Plus mobo, the M.2 socket is only x2 (2 lanes) and that limited my samsung xp941 to 770 MB/s read, 574 MB/s write, which is shy of the 1200 MB/s read, 900 MB/s write the SSD is capable of.

As others above have, the NVMe SSDs are the ones to go for - the Samsung NVMe SM951 is due to be released here in mid july and is what i'll be jumping on, moving my xp941 to backup/clone drive. There was a pretty decent review / comparison over on Tomshardware.com re SATA/AHCI/NVME http://www.tomshardware.com/reviews/samsung-sm951-nvme-versus-ahci-sata,4137.html. NVMe jumps way ahead on random read/write IOPS.

There aren't that many Z97 boards that offer a PCIe 3.0 x4 M.2 socket

I moved the xp941 to an Addonics PCIe m.2 to PCI adapter card, and installed it in a PCIe 2.0 x4 slot and it's now running at full speed.

As to cooling - yes they do run hot. The SM951 is supposed to run a little cooler than my xp941 - i read 97C on the xp941, when rendering video files, with a non-contact thermometer. But the one concern i'd watch out for, and should motivate a user to installing active cooling (ie a fan) is the SM951 (AHCI version) has a thermal limiter built in to drop performance down when temp hits 82C - iirc, one reviewer saw read speeds drop to 2MB/s for a couple seconds every time temp hit 82C, then jump backup to full speed for a few seconds, then back down to 2 MB/s, and it kept cycling up/down like that - that would really put a dampner on performance.

here's a shot of my xp941 mounted on the addonics card, with a fan directly overhead - the only spot that gets hot is the controller, about 3/4" x 3/4" directly under the "IC circle 20" on the label

after the fan installation, max temp i've seen is 77-78C - i'm thinking about playing with pulling that label back enough to uncover the controller, and help temps drop a little lower - that label is plastic and basically serving as an insulator, keeping heat from transferring out

One other item to look out for when selecting a mobo - most mfgrs are euphemistically describing the M.2 socket as "sharing bandwidth with sata ports x & x" - in my case it was sata ports 5 & 6. What they should have said was that when an SSD is installed in the M.2 socket, those two sata ports are dis-abled automatically. I think it was AsRock that used similiar "non-clear" language in their marketing and specifications list.

fwiw

 

[VirtualLarry]

Driver via the BIOS? The DRIVER is built into Win 8, and just needs to be downloaded and pointed to during a Win 7 install.

So you've successfully run a PCI-E NVMe SSD in an M.2 slot, in Windows 7, by downloading the Windows 8 driver, and presenting it to the Windows 7 installer? Does the Windows 8 NVMe driver come with Windows 7 .inf and .cat files?

 

[bradly1101]

So you've successfully run a PCI-E NVMe SSD in an M.2 slot, in Windows 7, by downloading the Windows 8 driver, and presenting it to the Windows 7 installer? Does the Windows 8 NVMe driver come with Windows 7 .inf and .cat files?

No, the drive manufacturer supplies a Win 7 NVMe driver (as Intel does) and during setup when it shows you a blank screen where the install drive should show up, just hit 'Load Driver' and point to that Win 7 driver on a USB drive (inf and dependent files), and you're good to go. Or you could slipstream it directly into the Win 7 install disk.

Mine is on an older X79 board, so I can't boot to the 750, which turns out to be just fine. It runs full speed on the PCIe 3.0 slot for programs and data I want really fast access to. Edit: I also keep my virtual memory, Photoshop scratch, and other programs' movable cache/database files on the 750.

Without trying to dis Samsung (I like their phones) I would stay away from their SSD's for reasons of M.2 heat and firmware/data retention problems with their other SSD's.

Don't forget; to use M.2 NVMe drives at full speed, you need a 4x slot. Otherwise the PCIe slot one is the way to go.

 

[bradly1101]

So you've successfully run a PCI-E NVMe SSD in an M.2 slot, in Windows 7, by downloading the Windows 8 driver, and presenting it to the Windows 7 installer? Does the Windows 8 NVMe driver come with Windows 7 .inf and .cat files?

It's all explained right here:

http://www.pcper.com/reviews/Storage/Video-Perspective-Installing-Windows-Intel-SSD-750-Series

 

[Fun Guy]

Anyone else have input?

 

[Railgun]

Specific to your question...most should be this, but you want an M keyed M.2 slot. Secondly, you want an NVMe drive.

You didn't say what OS you're running.

Bradly, I don't know what you're saying about...

Don't forget; to use M.2 NVMe drives at full speed, you need a 4x slot. Otherwise the PCIe slot one is the way to go.

That should read: If the M.2 slot on your mobo uses a PCI-E 3.0 x4 lane, you're good, otherwise, use a riser card for that spec with an M.2 slot.

Lastly, for which SSD you should use, read reviews and match the price to performance you're looking for. As bradly mentioned, the Intel 750 is the top dog for most things now other than price.

 

[Shmee]

If you could, I would go with one of the 750s, at least at this point. Asus makes a "hyperkit" adapter that turns an m.2 port into a SAS connector, going to the connector on the 2.5 in version of the 750. (or other enterprise 2.5 " NVMe SSD, which would be much pricier)

Note the adapter has issues with the design of the Asus ROG RVE board, due to where the m.2 slot is on the board and the length of most high end video cards.

However, it is a good solution for other boards if you dont want to use the PCIE add in card version, which could get in the way of SLI or Crossfire setups.

 

[Shmee]

Hmm, I was talking about X99, I noticed you were looking at micro ATX Z97 boards. Well, I certainly would not limit it to micro ATX Z97 IMO, you will get more features from an ATX board. However, if you don't want to pay for X99, I would recommend waiting for Windows 10 and Skylake, unless there is a great Z97 board you can settle on that meets all your needs and supports the full 3.0 X4 lanes for its m.2. You might need a BIOS update for using the hyperkit adapter fyi.