Understanding M.2 NGFF SSD Standardization (Or The Lack Of)

SO WHAT ABOUT PCI EXPRESS 3.0?

At 8GT/s, PCIe can theoretically attain 985MB/s per lane, compared to PCIe 2.0 which reached 500MB/s.  Present hardware is shipping with PCIe 3.0 and, in fact, our ASUS Maximus VI motherboard is PCIe 3.0, as are several of out M.2 adapter cards.  The PCIe 3.0 spec has a host of optional features that may or may not be a simple FW upgrade for manufacturers of SSD controllers. The speed from 5Gb/s to 8 Gb/s is likely a HW chip spin for most, and at least according to the LSI Marketing Team, we will likely not see 8Gb/s in the SF3700 and it will most likely be a derivative product from the SF3700 line.

CAN WE UPGRADE M.2 SSDS FROM SATA TO NATIVE PCIE?

Several e-mails have been received asking this question and, as we stated above, M.2 SSDs SATA SSDs cannot be switched with PCIe X4 M.2 SSDs and vice versa. We had both Sony VAIO Pro 13 ultra books in hand and it couldn’t be done.  The Samsung XP941 was not recognized in our M.2 SATA based VAIO, and the Toshiba SATA M.2 SSD was not recognized in the M.2 PCIe based VAIO. The reason might be a bit unsettling to most but, standardization relates to the M.2 host and not to the way it is connected to a system board. I know what the Gods intended but this is the reality of M.2 today.

CAN WE UPGRADE M.2 SSDS FROM SATA TO PCIE X2?

Prior to LSI AIS, we had spoken to several and all agreed that SATA and PCIe X2 couldn’t be switched, even though the same host connector was in use. The common theme has always been that data had to travel via PCIe or via SATA and there was no way around this.  A close contact at the conference did tell us, however,  that their company had been able to enable auto detection of the SSD (for M/B key only) at the system level with BIOS customization.  Remotely, this made sense as the system BIOS has been the constant wall that we hit when trying to adapt a native PCIe SSD as a boot device. To date we are not aware of any motherboard that will recognize the native PCIe SSD and enable it to boot.

AND WHAT ABOUT APPLE?

I knew you were going to go there and, initially, the Gods believed that they could rope Apple into this standardization.  Unfortunately they haven’t.  To their credit,  Apple was the first to ship a native PCIe SSD in their 2013 MBA and that SSD being a modified Samsung XP941 to boot.  Who would have figured? In fact, I am writing this article on my 2013 MBA that I still don’t know whom to thank for sending it along.   But that’s another story.

At least in the first run of their new systems, Apple has dedicated a custom PCIe solution to their entire MBA line, much like the XP941 M.2, except this one runs on two PCIe lanes vice the four of the Samsung XP941 we reviewed. We have heard recent rumblings that some have reached 1.2GB/s in the newest MBP/iMac releases and this would mean a X4 connection, however, we have been unable to validate such. Lastly, we should provide a heads up with respect to purchasing a new Mac with a low capacity SSD; they are much slower with write performance hitting the low SATA 3 realm at just over 300MB/s.  The only upgrade is through Mac and get ready to pay the price in that respect.  Did you wonder why Apple continuously alters their SSD in every generation to ensure they are proprietary?

M.2 FROM THE CONSUMER PERSPECTIVE

Marketing any product is a funny animal.  For the most part, it is most effective with those less educated in their purchases and this is most abundant in the SSD industry today. This is very evident with advertised SSD performance that most consumers would never be able to achieve in typical use.  With a bit of great press though, many consumers can now understand performance variables and identify when an ultrabook is marketed containing a sub 300MB/s SSD, vice the standard SATA 3 speeds of 550MB/s.  This was done and many learned the hard way.

Today, M.2 SSDs are all the rave and, with videos such as this, will hit just as fast as mSATA SSDs did a short time ago.  You wouldn’t believe the number of offers we have received for our M.2 SSDs from concerned consumers who thought we just might have too many on hand. Conversely, we have also received the unfortunate complaints of those who purchased M.2 SSD enabled systems, learning only after the fact that they were configured with SATA M.2 SSDs, rather than the high power PCIe based SSDs as advertised. Would you think a 2X plus performance difference is worthy of mention?

FINAL THOUGHTS

Lastly, I will be the first to state that I don’t consider myself an expert in any way and am simply a tech nut lucky enough to get some great stuff ahead of the rest and put together a few opinions.  Can I be wrong? Absolutely!  Have I been wrong?  Yes, but please don’t mention it to Karen. Have I ever made similar errs in opinion? It wasn’t three weeks ago that a peer slapped me on the wrist for my incorrect use of the term ‘interface’ in a report.  This information is no more than my experience, enhanced through great conversations with those friends that truly know flash storage.  If you can add to this, in any way, please do and include support for your thoughts.