Samsung SM951 (512GB) PCIe SSD Review

Final 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.