# SATA 3 - M.2 SSD



## DeNeDe (Apr 16, 2014)

The current SATA 3 6GB/s SSD would have any chance to be compatible with the  M.2 10GB/s ?
With some sort of adaptor to take full advantage of the 10GB/s ?


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## TheBrainyOne (Apr 16, 2014)

No.


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## wrathchild_67 (Apr 16, 2014)

Actually, according to the Wikipedia page for the M.2 spec, it may be possible to use older SATA devices with M.2 via an adapter since the M.2 spec does offer a legacy device interface for SATA 3.


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## thebluebumblebee (Apr 16, 2014)

DeNeDe said:


> The current SATA 3 6GB/s SSD would have any chance to be compatible with the  M.2 10GB/s ?


Yes.


DeNeDe said:


> With some sort of adapter to take full advantage of the 10GB/s ?


No.  Just because you plug something into a faster interface does not make that item faster than it was designed.  Plugging a SATA II HDD into a SATA III port does not make it a SATA III HDD.


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## DeNeDe (Apr 16, 2014)

I think most SSD SATA 3 6GB/s are faster than this. The limitation was only from the SATA 3 part. That's why I'm assuming that on the M.2 will be faster.
So how would the SATA 3 be compatible with M.2 ? Just plug in *OR* mobo manufacturers will provide some sort of adaptor like i've saw a while ago with the Sata-Express demo ?


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## thebluebumblebee (Apr 16, 2014)

Although today's SSD's may have the ability to go faster than the SATA III interface, they are built with that interface and are limited by it.  If you connect a 1" pipe to a 2" pipe, does flow rate in the 1" pipe increase? (assuming everything else stays the same) You can only run so fast.  The speed that you run is not determined by the speed limit of the road that you are on.  You can not run faster on a freeway than you can on a residential street with a 25 MPH speed limit.  Putting on Usain Bolt's shoes is not going to make you run as fast as Usain Bolt.


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## thebluebumblebee (Apr 16, 2014)

I've only seen 1 picture of a M.2 connector.  It seems to have been made with laptops in mind and looks similar to the mSATA connector on some motherboards.  I can see no benefit to connecting a SATA device to a M.2 connector.  There might even be penalties for using an adaptor.
Here, maybe this will help: http://rog.asus.com/308552014/label...a-and-sata-express-the-differences-explained/


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## DeNeDe (Apr 16, 2014)

I just purchased a Samsung 840 PRO 256Gb  that's why i'm asking.


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## TheBrainyOne (Apr 16, 2014)

DeNeDe said:


> I just purchased a Samsung 840 PRO 256Gb  that's why i'm asking.



The MDX controller can do 1.1 GB/s sequential reads and 0.9 GB/s sequential writes, but you are limited by the interface. Sorry bro, you should have waited. LSI Sandforce SF3700 SSDs will be reaching 1.8 GB/s sequential reads and at least 1 GB/s sequential writes when they come out.


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## DeNeDe (Apr 16, 2014)

TheBrainyOne said:


> The MDX controller can do 1.1 GB/s sequential reads and 0.9 GB/s sequential writes, but you are limited by the interface. Sorry bro, you should have waited. LSI Sandforce SF3700 SSDs will be reaching 1.8 GB/s sequential reads and at least 1 GB/s sequential writes when they come out.



Any price on that!?


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## Disparia (Apr 16, 2014)

When they were drafting the new standards they decided for whatever reason (high on crack?) they would allow manufacturers to produce SATA based SSDs for M.2 slots. Instead of having those manufacturers use a controller as they do with current PCIe to SATA devices, they decided to have it take a SATA channel from the chipset's controller. That part at least makes sense, limited space on M.2 PCB and most people aren't utilizing the 6 ports they usually have.

As you can see from the pic the SATA port is only connected to a few pins which are connected to your chipset's (or SoC, or perhaps any) SATA controller. In other words, drives connected to it are not going to benefit from the PCIe interface at all. The upside is that an adapter is just like any other port on your motherboard with no conversion from one standard to another.


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## TheBrainyOne (Apr 17, 2014)

DeNeDe said:


> Any price on that!?


The XP941 is currently an OEM only SSD. XP941 is basically an 840 Pro using PCIe 2.0 x4 as it's interface instead of SATA 3.

SF3700 based SSDs will be launching around the end of the year.


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## DeNeDe (Apr 17, 2014)

Hmm...until they are released will use the 840 Pro for Windows and stuff. After that will purchase some M.2 SSD.
I hope prices to be not very high.
Good for me I have a Velociraptor HDD at 10.000RPM


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## RamCity (May 6, 2014)

DeNeDe said:


> I think most SSD SATA 3 6GB/s are faster than this. The limitation was only from the SATA 3 part. That's why I'm assuming that on the M.2 will be faster.
> So how would the SATA 3 be compatible with M.2 ? Just plug in *OR* mobo manufacturers will provide some sort of adaptor like i've saw a while ago with the Sata-Express demo ?



M.2 is an interface standard that supports being connected to both the SATA bus and/or PCIe interface, using up to 4 lanes.  It's when the M.2 socket is wired to the PCIe bus that performance exceeding the usual SATA speeds is possible.  Sadly though, very manufacturers are yet to embrace this and most have M.2 sockets that are connected to the SATA bus only.  The exception being Asrock which has a dual PCIe x2 / SATA M.2 socket motherboard.


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## RamCity (May 6, 2014)

TheBrainyOne said:


> The MDX controller can do 1.1 GB/s sequential reads and 0.9 GB/s sequential writes, but you are limited by the interface. Sorry bro, you should have waited. LSI Sandforce SF3700 SSDs will be reaching 1.8 GB/s sequential reads and at least 1 GB/s sequential writes when they come out.



A lot of people talk about the LSI Sandforce SF3700 SSDs with great enthusiasm, but I think it will be a while before we see this technology available at a consumer accessible price.  

Recent benchmark results which are about to be published will show that a PCIe 2.0 socket with 4-lanes of connectivity will max out at about 1.5GB/s.   I think the technology will need to move up utilising 8 PCIe 2.0 lanes on the SSD, or to PCIe 3.0.   Since manufacturers are now only just releasing SSD's using just 2 PCIe lanes (think Plextor M6e - PCIe 2.0 x2) and the Samsung XP941 (PCIe 2.0 x4), I figure it will be a while before the next generation of products become available with the speeds promised by the LSI Sandforce SF3700 controller.


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## TheBrainyOne (May 6, 2014)

RamCity said:


> Recent benchmark results which are about to be published will show that a PCIe 2.0 socket with 4-lanes of connectivity will max out at about 1.5GB/s.


The 1.5 GB/s limit was mentioned in Anandtech's review of M6e.

I never mentioned price or the timeframe of when we'll get 1.8 GB/s SSDs. I just mentioned that whenever they come out, they *should* reach those speeds.


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## RamCity (May 6, 2014)

TheBrainyOne said:


> The 1.5 GB/s limit was mentioned in Anandtech's review of M6e.



I didn't know that.  Could you link to the review where he made that discovery?  I couldn't see that reference in the two reviews I found.  The maximum transfer rates I've seen quoted so far is 770MB/s on the single drive, unless you are talking about two drives striped in a RAID setup?



TheBrainyOne said:


> I never mentioned price or the timeframe of when we'll get 1.8 GB/s SSDs. I just mentioned that whenever they come out, they *should* reach those speeds.



Sorry, I didn't mean to try and dampen your enthusiasm.  I'm looking forward to seeing the LSI Sandforce SF3700 SSD's as well.  Just adding another perspective.


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## TheBrainyOne (May 7, 2014)

RamCity said:


> Sorry, I didn't mean to try and dampen your enthusiasm.  I'm looking forward to seeing the LSI Sandforce SF3700 SSD's as well.  Just adding another perspective.



It's alright. The SSD and GPU are the only interesting sections of the enthusiast PC market, anyway.

Here's the Anandtech article:
http://anandtech.com/show/7843/testing-sata-express-with-asus


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## RamCity (May 7, 2014)

TheBrainyOne said:


> It's alright. The SSD and GPU are the only interesting sections of the enthusiast PC market, anyway.
> 
> Here's the Anandtech article:
> http://anandtech.com/show/7843/testing-sata-express-with-asus



Excellent article!  

A practical application of the 1500MB/s limit Kristian is talking about in the above anandtech article is also illustrated in this review from barefeats.com.  Note how when just 4-lanes of PCIe 2.0 is available, that the 2x XP941's in RAID saturate the interface at about 1500Mbs, whereas they can actually achieve 2200MB/s once additional PCIe lanes are available.


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## TheBrainyOne (May 8, 2014)

RamCity said:


> Excellent article!
> 
> A practical application of the 1500MB/s limit Kristian is talking about in the above anandtech article is also illustrated in this review from barefeats.com.  Note how when just 4-lanes of PCIe 2.0 is available, that the 2x XP941's in RAID saturate the interface at about 1500Mbs, whereas they can actually achieve 2200MB/s once additional PCIe lanes are available.


http://www.thessdreview.com/our-rev...-0-worlds-smallest-ssd-combination-hits-2gbs/


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