Samsung SM951 (512GB) PCIe SSD Review
by Kristian Vättö on February 24, 2015 8:00 AM ESTFinal Words
When the news that the SM951 isn't NVMe enabled hit the Internet, there was a lot of disappointment around. Understandably many were expecting that the SM951 would merely be an evolutionary step from the XP941 because AHCI command set would still limit the full potential of the PCIe interface, but Samsung proved us all wrong. The SM951 is far from being a marginal step up from the XP941 because in most of our tests the SM951 beats the XP941 by a 50-100% margin. As a matter of fact, the upgrade from XP941 to SM951 is bigger than going from a SATA 6Gbps SSD to the XP941. Despite the lack of NVMe, there's no arguing about the fact that the SM951 is the fastest client SSD and by a very healthy margin.
From a performance perspective I have absolutely no complaints aside from thermal throttling. I wouldn't consider it to be a major issue because regardless of some throttling in synthetic tests, the SM951 is easily the highest performing drive. The Destroyer test takes about 10 hours to run on modern drives, so if throttling was a real issue it would show up more clearly in the results too. Besides, my half-open testbed isn't ideal for airflow either, but since I haven't encountered noticeable throttling in the past I wanted to mention it in case anyone runs into performance issues with the drive.
Right now the biggest issue with the drive is its nearly nonexistent availability, though. If you want to get your hands on the drive today, the only known way to do that is to buy Lenovo's ThinkPad X1 Carbon that is configured with a PCIe SSD. The cheapest configuration with a 512GB SM951 comes in at $1,709.10, so there's practically no sane way to get access to the drive (unless, of course, you want the X1 Carbon laptop as well and are willing to pay the price).
That brings us to the next subject. Since retail availability isn't expected until late May at the earliest, there's a chance that the SM951 will no longer be the fastest SSD once it's actually available for purchase. At CES last month, several SSD vendors told me that they should have PCIe SSDs ready for Computex, which is in early June, i.e. right after the SM951 is scheduled to start shipping.
If the SM951 was available today, I would have no reason not to give it our "Recommended by AnandTech" award. Being hands down the fastest client SSD on the market is enough justification for the award, but because the drive won't be shipping for several months I can't be sure that I'm still recommending the SM951 once it's available. For now the only thing we can do is wait, but at least we can do it in peace by knowing that the future is quick and bright.
Facebook
Twitter
RSS
128 Comments
View All Comments
peevee - Friday, March 20, 2015 - link
IOmeter? Packing several weeks/months of IO into a several minutes/hours test? Seriously, your tests have become SO artificial as not to correspond to any real life experiences at all. For example, in real life SSD write speed almost does not matter, because almost always they are asynchronous - write happens into cache and user does not wait anything, or speed of writes is limited by the speed of data acquisition - case in point, you download test is always limited by much slower internet speed, or copying pictures off camera/SD card are limited by much slower camera/reader, USB or SD speeds etc. Background backup, happening without a user AT ALL? Come on!It would be actually much more interesting to see at least a few REAL numbers, like good old starting Windows or copying a catalog full of pictures and videos or starting a VM. So the users would see what amount of their time they would REALLY save by investing extra into a faster drive.
kishisaki - Tuesday, April 7, 2015 - link
How did you get all those speed with Asus Z97 Deluxe?I thought it only has a 10Gb/s M.2 Slot?
Gradius2 - Wednesday, April 15, 2015 - link
My solution is WAYYYY cheaper and bigger, I have 670GB (real size) on my little RAID, see the performance: http://i61.tinypic.com/2vt9mo6.jpgxyvyx2 - Wednesday, July 22, 2015 - link
I was able to keep the temps down on my SM951 by attaching a small heatsink... I need to do some data logging, but I don't think it's gone over 60C since:http://s76.photobucket.com/user/xyvyx/media/Comput...">[IMG]http://i76.photobucket.com/albums/j9/xyvyx/Compute...[/IMG]
stevae - Wednesday, August 12, 2015 - link
why isn't there a trouble shoot included IF your result comes back that the drive DOES NOT have trim working? this is incomplete article.Invisibleman - Sunday, August 16, 2015 - link
Kristian,Because I didn't read this review earlier and I am now planning to upgrade my PC to an M2 SSD. I came to this review.
But there is one thing I realy don't understand. As the setup is saying, you have tested with de Asus Z97 DeLuxe. I know there are 2 different versions of this one. 1 is with USB 3.1 support (new version) and 1 with USB 3.0 (Old one) this one I have.
But if I look at the specs then the Z97 DeLuxe shares the bandwide with SataExpress 1 and have only 2 x PCI Express 3.0/2.0 x 16 Slots (Single at 16x or dual at x8/x8 Mode)
But as I read the SM951 needs to have PCI 3.0 x 4bus. Am I missing something? For me it seems that the SM951 can't run full speed on this board. If it goes thru Sata Express then also get only PCI 3.0 X 2. But in the test (charts) you are mention PCI 3.0 x 4. How is this possible to get if the Max is PCI 3.0 x 2?
So can you tell me what I am missing? What do I need to do/buy extra to get this one run one full power meaning PCI 3.0 x 4.
Regards,
Hans
Hoogmade - Monday, December 7, 2015 - link
What card is used to use the SM951 in a Mac Pro 2012?I tried the Addonics ADM2PX4 but that doesn't seem to work.
dtscaps - Friday, March 11, 2016 - link
Ok, this is supposed to be a review to guide me what SSD to buy. I read 10 pages of performance specs and 72 more comments dealing with microseconds marginality. The fact that this drive does or does not have an AES self encrypting mechanism adering to OPAL 2 with a possible IEEE1667 extension IS IMPORTANT. IT IS A COMPLETE SHOW STOPPER if the drive cannot encrypt data. Maybe except if you are a kid playing with new toys.So, is this SSD self encrypting ?
Does it support Opal 2
Does it support the IEEE1667 extension?