After shipping two generations of M.2 drives with PCIe interfaces for OEM customers, Samsung is releasing a PCIe drive to the retail market which has the added benefit of including the latest features Samsung offers. The Samsung 950 Pro is the new flagship consumer drive and it eschews the backwards compatibility and the 2.5" SATA form factor of the three previous iterations of the 8xx Pro family in favor of a PCI Express 3.0 x4 connection in the M.2 2280 form factor coupled with the NVMe protocol. Those changes allow for one of the biggest generational performance jumps in the history of the SSD industry and should help the transition of SSDs shedding the last vestiges and limited feature sets of their mechanical hard drive predecessors.

The M.2 2280 form factor has the potential to unify the consumer SSD market, with a physical size small enough for ultrabooks but a large enough capacity for all users. M.2, depending on the exact implementation used by the OEM, has the ability to provide SATA or high-performance PCIe connectivity, easing the transition. By supporting up to four lanes of PCIe 3.0, M.2 has helped make the two-lane SATA Express standard dead on arrival and ensures that drives won't be starving for bandwidth again for quite some time.

Meanwhile, high-end SSDs have been struggling to squeeze every last drop of performance out of the 6Gb/s SATA III interface. While some vendors have put out M.2 PCIe devices that support two lanes of PCIe, Samsung went straight for four lanes with the XP941 drive for OEMs to start. This was then upgraded to PCIe 3.0 speeds with the SM951. Earlier this year, they implemented the NVMe protocol which allows the SM951 to make use of the available bandwidth of the PCIe 3.0 x4 link. With Intel's Skylake platform bringing plentiful I/O bandwidth to support multiple lanes of PCIe 3.0 to more than just the graphics card, a good number of external bottlenecks are bypassed and Samsung can stretch the true capabilities of the hardware. This is a main focus of the 950 Pro.

Samsung SSD Comparison
  950 Pro
950 Pro
SM951-NVMe 512GB (OEM) 850 Pro
Form Factor M.2 2280 2.5" SATA
Controller Samsung UBX Samsung MEX
Interface PCIe 3.0 x4 SATA III
Protocol NVMe AHCI
DRAM 512MB 512MB 512MB
NAND Samsung V-NAND 32-layer 128Gbit MLC Samsung 16nm 64Gbit MLC Samsung V-NAND 32-layer 86Gbit MLC
Sequential Read 2,500MB/s 2,200MB/s 2,150MB/s 550MB/s
Sequential Write 1500MB/s 900MB/s 1,550MB/s 520MB/s
4KB Random Read (QD32) 300K IOPS 270K IOPS 300K IOPS 100K IOPS
4KB Random Write (QD32) 110K IOPS 85K IOPS 100K IOPS 90K IOPS
Power 7.0W (burst)
5.7W (average)
1.7W (idle)
6.4W (burst)
5.1 (average)
1.7W (idle)
8.9W (peak) 3.3W (read)
3.0W (write)
0.4W (idle)
Encryption AES-256, TCG Opal 2.0 N/A AES-256, TCG Opal 2.0
Endurance 400TB 200TB N/A 300TB
Warranty 5 Year N/A 10 Year
Launch Date October 2015 ~June 2015 July 2014

The 950 Pro is using the same UBX controller as the SM951, but pairs it for the first time with 3D NAND. We first saw Samsung's 128Gb 32-layer V-NAND in the 2TB 850 Pro, introduced about a year after the original 850 Pro. None of the major components of the 950 Pro are entirely new, but this is the first consumer level product to combine them. The 950 Pro is an aggressive push forward; it's a bit risky to be bringing so much new tech in one product to the unforgiving retail market. Samsung will bear the brunt of any immaturity or incompatibilities, but they are hoping to lead the way for a much broader shift in the market.

PCI Express has been around for a long time and offers forward and backward compatibility, but until very recently most systems only offered 16 lanes from the processor, mainly for graphics cards, and one-lane slots for anything else from the chipset. With Intel's Haswell generation of processors the SATA Express connector and M.2 slot started appearing, but systems with a four-lane PCIe 3.0 connection available (and with enough overall bandwidth to fully feed it) are still quite rare. As a result, most consumers could only get that much bandwidth from one of their graphics card slots, moving any discrete graphics card to half PCIe bandwidth. This changes with Skylake and the 100-series chipsets that can support 20 PCIe 3.0 lanes of connectivity through the chipset, and up to three PCIe 3.0 x4 drives in Intel's RST mode for RAID combinations.

The 950 Pro is the new flagship, but it is certainly not a replacement for the 850 Pro. The pricing reflects that: $200 MSRP for the 256GB and $350 for the 512GB is about 50% higher than current retail prices for the 850 Pro, which is still one of the top performing consumer SSDs. Samsung is betting that the market is ready for a new premium category that's meant to be a part of the newest and fastest machines.

The 850 Pro will be sticking around in its current role, and as it's refreshed to use the 128Gb V-NAND the range of capacities will expand further, with a 4TB model of the 2.5-inch drive due in early 2016. The switch to 128Gb V-NAND may also allow prices to drop and widen the gap between the 850 Pro and the 950 Pro.

AnandTech 2015 SSD Test System
CPU Intel Core i7-4770K running at 3.5GHz (Turbo & EIST enabled, C-states disabled)
Motherboard ASUS Z97 Deluxe (BIOS 2501)
Chipset Intel Z97
Chipset Drivers Intel 10.0.24+ Intel RST
Memory Corsair Vengeance DDR3-1866 2x8GB (9-10-9-27 2T)
Graphics Intel HD Graphics 4600
Graphics Drivers
Desktop Resolution 1920 x 1200
OS Windows 8.1 x64
Testing With NVMe Over PCIe


View All Comments

  • herbc - Friday, October 23, 2015 - link

    How fast do you really need to be happy with using a computer is my question , my computer is faster now than i actually need it to be and all it has is a current SSD . Reply
  • Woff - Friday, October 23, 2015 - link

    I have a system with Asus X99 DeLuxe motherboard and a I7-5960X cpu. I use a Samsung 850 EVO 500GB SSD connected to one of the SATA ports, but I want to upgrade this device to a M.2 Samsung 950 Pro. The motherboard offers two ways to connect a M.2 but I don't know witch is the best alternative. The X99 has a on-board M.2 (socket3) but is also delivered with a expansion card, a 'HYPER M.2 x4' card. Anyone who can help me with the best (fastest) solution to my problem? Reply
  • Redstorm - Friday, October 23, 2015 - link

    You should be OK to use the Onboard M.2 slot as the manual says "32Gb transfer for the onboard M.2" page 'x' so 4 x PCIe 3.0 Reply
  • cjelliott - Tuesday, November 17, 2015 - link

    How did you get on with this 950 Pro SSD on the X99 Deluxe? Can you boot from it? I am tempted to buy this SSD but have seen a lot of forums where people are having trouble. I want to install and boot Win 10 Pro from it. Reply
  • l_d_allan - Saturday, October 24, 2015 - link

    Hmmmm ... the Samsung Galaxy review was at the top for 5 days, then one day for an ASUS mother board, and only one day for the Surface 4, and now several days for the Samsung PCie SSD.

    Seems unbalanced. Or just "the luck of the draw"?
  • Kristian Vättö - Sunday, October 25, 2015 - link

    Usually content is only released on weekdays, so reviews that go up later in the week (e.g. on Thursday) may get several days of page time. Oftentimes the content release is dictated by an embargo lift, so the time of publishing isn't on AnandTech's hands.

    I can assure you that this is just a coincidence - there's no rule or contract that a certain company must get X number of days at the top. Frankly, it wasn't even something we thought about during my time at AnandTech as content always went up when it was ready and free for publishing.
  • Craig234 - Saturday, October 24, 2015 - link

    "The Intel SSD 750 clearly needs to come down in price to be completely sidelined by the 950 Pro. "

    I think you mean to AVOID being completely...
  • TheBeagle - Saturday, October 24, 2015 - link

    I case anybody is interested, has this lovely items for sale (pre-order) right now. The Amazon web site says the product will be released for sale on Thursday, October 29th. Hurry up before they're all gone - LOL! Beagle Reply
  • FXi - Saturday, October 24, 2015 - link

    I know it's not a lot of space but some degree of power loss protection would have been proper for a "pro" device in this price category. Reply
  • Kristian Vättö - Sunday, October 25, 2015 - link

    The 950 PRO, just like all Samsung client SSDs, do journaling to protect the FTL against sudden power losses. Protection for cached user data is not really needed since modern file systems have been designed to withstand minor data losses (HDDs also use DRAM to cache writes, so SSDs are no different in that sense). Reply

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