M.2, mSata, mPCIe SSDs

[Mand]

In the process of putting together a plan for a new build, I started noticing some new storage options that I was unfamiliar with, and I'm rather confused. I like the idea of not having to run SATA cables through things as well as put the otherwise-vacant PCIe slots to good use, but I'm not sure exactly how the compatibility works.

Are M.2, mSata, and mPCIe completely incompatible, or are any of them the same thing? Do some of them require specific additional things to add to plug them into for say PCIe slots? To use an example, what kinds of SSDs could I put into a board like the ASUS Maximus VI Forumla? What kinds can't go in that slot?

And is any of this really worth it just to not have to mount 2.5" drives and route SATA cables?

 

[Hellhammer]

All three are form factors that are mainly meant for laptops and other mobile devices due to their small size. They all require a specific slot or adapter (i.e. can't connect mSATA to a regular SATA connector).

mSATA and mPCIe share the same connector and overall PCB layout, but electrically they are different (mSATA is routed to the IO controller, mPCIe to the PCIe controller). Some boards may also have slots that function as both mSATA and mPCIe.

M.2 is the successor of mSATA and uses a different connector (i.e. not compatible with mSATA or mPCIe). Electrically it supports both SATA and PCIe interfaces.

The ASUS Maximus VI Formula is a unique motherboard in the sense that it supports M.2, which is rare at this point. However, it's limited to just one PCIe 2.0 lane (500MB/s) and is hence slower than SATA 6Gbps. It also has an mPCIe slot, although mPCIe SSDs are quite hard to find.

To be honest, currently there is no point in using something else than 2.5" SATA SSDs in a desktop build.

 

[Mand]

Well, from my understanding, the mPCIe slot in that particular board is taken up by the wireless card that comes with it.

But yeah, that's what I've been able to piece together - stick with 2.5" drives. The 500MB/s part really stings - isn't higher data rates the point of going to SSD in the first place?

Thanks for the info.

 

[RU482]

personally I'd go the 2.5" SSD route...usually easier to find deals on 2.5" drives vs mSATA or M.2

 

[Hellhammer]

The 500MB/s part really stings - isn't higher data rates the point of going to SSD in the first place?

Yes. I'm not sure why ASUS has made the decision to only dedicate one PCIe lane for the M.2 slot but there aren't even many M.2 SSDs available in retail and most of those are SATA 6Gbps designs anyway.

 

[Aikouka]

Yes. I'm not sure why ASUS has made the decision to only dedicate one PCIe lane for the M.2 slot but there aren't even many M.2 SSDs available in retail and most of those are SATA 6Gbps designs anyway.

Because more lanes just isn't necessary. The M.2 slot on the Maximus VI Formula (and the Maximus VI Impact) has very little clearance and only supports the smallest M.2 size (22mm x 42mm). At this point, I don't see a small drive with that number of NAND modules ever saturating 500MB/s.

 

[Hellhammer]

Because more lanes just isn't necessary. The M.2 slot on the Maximus VI Formula (and the Maximus VI Impact) has very little clearance and only supports the smallest M.2 size (22mm x 42mm). At this point, I don't see a small drive with that number of NAND modules ever saturating 500MB/s.

In theory 500MB/s can be saturated even with just two NAND packages. Reading 16KB from IMFT's 20nm 128Gbit MLC NAND takes 115µs, which translates to ~140MB/s of throughput. With two packages you get up to 16 dies and 2.24GB/s of theoretical read throughput. When taking the interface bottleneck (ONFI 3.0 is 333MB/s) into account, we're still at 666MB/s (theoretically speaking).

E.g. the 120GB and 250GB EVO mSATAs only have two NAND packages, yet they're able to saturate the SATA 6Gbps bus in terms of sequential read throughput.

Nitpicking aside, I didn't recall that ASUS' implementation only supports the smallest M.2 so thanks for the clarification. The 500MB/s makes more sense now and the slot itself is even more useless.

 

[BrightCandle]

At some point in the near future however these new interfaces are going to start having more lanes and start showing significantly high peak performance than a 2.5" SSD. I am think an M2 or mPCIe SSD is my next SSD upgrade as the future is certainly going that direction for performance reasons as SATA just doesn't have the bandwidth anymore.

 

[razel]

As excited as some of us are about M2 and PCIe SSDs, the show of such products from manufacturers at the latest CES was ho-hum. Apparently there were more showing the years prior. At 1st I was disappointed, however realistically even though UEFI has been available to consumers for the past 5 years, it'll take a few more years for boarder support for the average Joe, especially for booting.

Meaning 2.5" form factor is here for awhile. I'm glad. I'm still rocking, using and, enjoying everyday my Intel SSD from 2009, but obviously I'd love to jump over hardware SATA for SSDs.

 

[MichaelD]

This is very informative and would make a great sticky in this forum.

All three are form factors that are mainly meant for laptops and other mobile devices due to their small size. They all require a specific slot or adapter (i.e. can't connect mSATA to a regular SATA connector).

mSATA and mPCIe share the same connector and overall PCB layout, but electrically they are different (mSATA is routed to the IO controller, mPCIe to the PCIe controller). Some boards may also have slots that function as both mSATA and mPCIe.

M.2 is the successor of mSATA and uses a different connector (i.e. not compatible with mSATA or mPCIe). Electrically it supports both SATA and PCIe interfaces.

The ASUS Maximus VI Formula is a unique motherboard in the sense that it supports M.2, which is rare at this point. However, it's limited to just one PCIe 2.0 lane (500MB/s) and is hence slower than SATA 6Gbps. It also has an mPCIe slot, although mPCIe SSDs are quite hard to find.

To be honest, currently there is no point in using something else than 2.5" SATA SSDs in a desktop build.

 

[Turab]

M.2 is the solution to fix low bandwidth where mSATA lacks.

But it is also not sufficient yet. Only few companies trying to do something better.

I remember Asrock's AMD based lastest mobo had 10Gb/s M.2 slot:

http://www.asrock.com/mb/overview.us.asp?Model=Fatal1ty 990FX Killer


While SF-3700s are approaching, it is still worth to go with 10Gb/s ?

I don't think so.

 

[Charlie98]

This is very informative and would make a great sticky in this forum.

I would agree... this thread answered a bunch of questions that I wasn't smart enough to know how to ask.

The idea of mSATA or M.2 makes gobs of sense, particularly in small boxes that I'm seeing more and more of. Build it and they will come!