Samsung has been at the forefront of SSD technology for some time now. The 840 Evo was the first SSD to feature triple-level cell (TLC) NAND, while the SSD 850 Pro introduced us to 3D NAND. The new SSD 950 Pro, while not introducing any new technologies of its own, does merge a whole host of emerging standards into one tiny but incredibly powerful stick of solid state storage.
NVMe is a protocol that specifies a new means of communication between the system host and the SSD. Unlike AHCI, which is used on all SATA SSDs and modern hard drives, NVMe is specifically designed with NAND flash, PCI-E and multiple CPU cores in mind, aiming to exploit the massive parallelism present in modern systems. We’ve seen it put to use already in Intel’s SSD 750 series, but the 950 Pro is the first consumer M.2 drive to take advantage of it. Samsung technically already has an NVMe M.2 SSD, but it’s the OEM SM951 (unlike the 950 Pro, this also has an AHCI version). Physically, the new 950 Pro is very similar to the NVMe SM951. For instance, both drives use the popular M.2 2280 form factor and the PCI-E bus. Most X99 and Z170 motherboards support this size of M.2 drive and PCI-E storage; however, some of these boards and many laptops (especially older ones) will have SATA-only M.2 slots, so you’ll need to check if you’re planning an upgrade. Lastly, both drives require four PCI-E 3 lanes to function at full speed and, again, you’ll need to check your board’s capabilities – if your M.2 slot only supports PCI-E 2, or just two lanes, your speeds will be capped. The 950 Pro uses Samsung’s UBX controller, and pairs it with 512MB of Samsung LPDDR3 for cache and Samsung firmware. So far, it’s just like SM951. The difference, then, is the NAND, with Samsung moving away from planar/2D NAND to its 3D NAND tech now known as V-NAND. Specifically, it’s using its second-generation, 32-layer dies with a 128Gb capacity. There’s only room for two NAND packages on the 950 Pro, as Samsung has kept the drive single-sided to maintain compatibility and reduce thermal stress. As such, there are eight dies per package on the 256GB drive, and 16 per package on the 512GB drive. Samsung has also dropped the 128GB capacity seen in the SM951 range, but will introduce a 1TB SSD 950 Pro next year when it rolls out its thirdgeneration, 48-layer 256Gb V-NAND dies. Despite the new NAND, the 950 Pro’s performance isn’t much different to that of the SM951. The main differences come from one being a consumer drive and the other an OEM. For example, the 950 Pro has an all-black PCB, which may hold sway with enthusiasts, as it will look much better in almost any build than the bright green SM951. The main benefit you get, though, is a proper, Samsungbacked warranty of five years. It covers 200 TBW (terabytes written) for the 256GB drive or 400 TBW for the 512GB – that’s 33 per cent more TBW than the 850 Pro drives guarantee, although the warranty period is half as long. Either way, it’s a very generous offering that should leave you with little doubt about the drive’s endurance. You also get hardware-accelerated encryption with TGC Opal 2.0 support, or at least you will do through a future firmware update. Lastly, Samsung’s excellent Magician software has full support for the SSD 950 Pro. This software provides easy firmware updates, monitoring, manual overprovisioning, encryption implementation and secure erase features. Before we delve into the performance figures, we need to note that the results for the SSD 850 Pro 1TB are from a different test system to the X99 one we used here. We no longer had access to this sample at the time of testing, but wanted to include it anyway, given that it’s essentially the fastest SATA 6Gbps SSD around. CrystalDiskMark is a good tool for showing us maximum performance, and the SSD 950 Pro doesn’t disappoint. We saw sequential read speeds of 2.6GB/sec, dropping slightly to around 2.3GB/sec for the 256GB drive, with both results being pretty close to Intel’s 750. When it comes to write speeds, the 512GB drive is faster than Intel’s 1.2TB monster, hitting over 1.
5GB/sec, and the 256GB is no slouch either, hitting just under 1GB/sec. Meanwhile, the SATA SSD 850 Pro is still a fast SSD, of course, but it’s no match for these NVMe ones. That said, the real-world traces in PCMark 7 suggest that, while the new NVMe drives do have an advantage for everyday use, it’s much smaller than the CrystalDiskMark results suggest. The SSD 950 Pro SSDs lead their SATAbased sibling by 8-9 per cent in this test, and also have a very small lead over Intel too. The PCMark 8 traces, meanwhile, show no meaningful difference for general office tasks. Even game loading doesn’t seem to benefit much from the increased speed, with the 950 Pro only able to shave one second off the 850 Pro’s time. Only the Photoshop Heavy trace shows a significant difference, with all three NVMe drives completing the test around ten seconds faster than the 850 Pro’s six-minute time. Finally, the Iometer tests, which mimic heavy professional drive access patterns with a barrage of reads and writes at a high queue depth, show clear gains. Even the 256GB 950 Pro is more than twice as fast as the 1TB 850 Pro, as the additional PCI-E bandwidth and NVMe’s improved ability to deal with multiple CPU threads come into play. With its extra NAND dies, the 512GB drive is over a third faster still. However, victory goes to Intel here, which isn’t surprising, as the 750 is very much a professional-level SSD. The SSD 950 Pro is hands down the best M.2 SSD around. It matches staggering transfer speeds with an excellent warranty and solid feature set, and it even has an attractive black PCB. It’s bound to appeal to enthusiasts who want the best performance, especially those who are also into small form factors PCs, for which M.2 is a perfect match. That said, the cost per gigabyte is massive and the speed advantage will have little real-world impact for most home users compared with using a standard SATA SSD, which offers much better value for money.
An awesome show of SSD strength from Samsung and a great choice for high-end small form factor builds, but for most home users, a better value SATA SSD is still fine.
Interface M.2 4x PCI-E 3 (32Gb/sec)
Formatted capacity 238.
Memory Samsung 128Gb 32-layer V-NAND MLC
Warranty Five years (maximum 110GB/day or 220GB/day host writes).