— There are high failure rates for the 4TB version of this drive. After moderate use the drive can develop bad sectors which block file reads. Scandisk does not detect the errors and the data blocks are not recoverable. There are widespread reports of this problem but Samsung have yet to issue a statement.

— The 970 Evo Plus offers excellent sustained write performance both in and out of cache. This results in consistent performance even when the drive is nearly full. Samsung also have a great track record for reliability, this drive will likely last a lifetime. The larger capacity drives (1TB+) offer even better write performance and may be more appropriate for some users. We use this drive (and its larger siblings) extensively in our EFps Lab at UserBenchmark.

— Adata’s XPG SX8200 offers NVMe PCIe SSD performance at SATA SSD prices, thereby offering outstanding value for money to casual and power PC users alike. Adata have combined two high performance commodity components: a Silicon Motion controller (SM2262) and Micron’s second generation 3D TLC 64 layer flash memory. The XPG SX8200 also includes a generous SLC cache and a DRAM cache buffer. Adata have not specified the exact size of the SLC cache in each model but it’s clear from our 60 second sustained write tests that the buffer is sufficient for more than 60 seconds of continuous writes which equates to over 60GB (60s x 1 GB/s) for the 240GB model and over 90GB (60s x 1.5 GB/s) for the 480GB and 960GB models. Unlike many other drives with SLC caching, the SX8200 has a large enough cache to ensure that consumers will almost always operate the drive within the cache and therefore experience no write degradation at all. Adata offer a 5 year warranty and a limited TBW warranty (160 TBW for the 240 GB version, 320 TBW for the 480GB and 640 TBW for the 960GB) on these SSDs, which is in line with other premium manufacturers. The NVMe PCIe SSD consumer market has been dominated by Samsung in recent years but the 240GB SX8200 beats Samsung’s 250GB 970 Evo hands down on both price and performance (the 250GB 970 Evo is let down by a relatively small SLC cache which allows for less than 10 seconds of writes before saturation after which the write speed on the Evo drops to mere sub SATA 300 MB/s). The SX8200 is the new value leader and heralds a new era of competition for the mainstream segment of the NVMe SSD market.

— The Samsung 970 Pro is a third generation NVMe PCIe SSD which replaces the 960 Pro. It comes in a M.2. form factor and features Samsung’s latest Phoenix controller and 64 layer proprietary 3D MLC NAND. MLC NAND has better write consistency but is more expensive than the TLC NAND found in the 970 Evo. The 970 Pro demonstrates a 16% increase in peak sequential write speed over the 960 Pro. There are also improvements in random read and write speeds. Interestingly this iteration of Pro SSDs come with a price cut, with the 512GB retailing at just $250 and the 1TB at $500, whilst at the time of writing, the 512GB 960 Pro is $315. The 970 Pro targets professionals who may rely on Samsung’s 5 year or 600TBW warranty and who may need its extended write performance. But, for most users who rarely transfer more than 22 GB at a time (this is the size of the SLC cache the 500GB 970 Evo), the cheaper 970 Evo may represent better value for money.

— The 970 Evo is Samsung’s third generation NVMe PCIe SSD for high-end consumers and professionals alike. It employs the latest Samsung Phoenix controller and their latest version of TLC 3D NAND (now 64-layers) which is cheaper but with slightly lower endurance and weaker write consistency than the MLC NAND found in the 970 Pro. The 970 Evo comes in a M.2 form factor and four sizes: 250GB, 500GB, 1TB and 2TB. The $120 250GB 970 Evo has an advertised sequential read speed of up to 3400 MB/s (200MB/s faster than the 250GB 960 Evo) and a sequential write speed of 1500 MB/s which drops to 300 MB/s once the 13Gb of SLC cache has been exhausted (this is similar to the sustained write performance on the 960 Evo). Further benchmarks are required before we can attest to its overall performance in the real world. The anticipated modest performance improvement between generations is expected to maintain Samsung’s front running as the premium SSD brand. Samsung now offers a warranty of 5 years across the suite of 970 SSDs and specifically a generous write endurance of 150 TBW on the 250 GB 970 Evo, thereby challenging the need for the 970 Pro MLC variant.

— The MX500 is Crucial’s current flagship consumer SATA SSD featuring their latest second generation 64-layer 3D TLC NAND. It’s available in 250 GB, 500 GB, 1 TB and 2 TB capacities in a 2.5-inch form factor. All but the 2 TB version will also be available in M.2 (2280) form in the future. The MX500 features a Silicon Motion SM2258 controller which is a change from the Marvell 88SS1074 controller featured in the MX300 (it’s nearly two year old predecessor). Performance is around 30% better than on the MX300 which currently retails at the same price. The MX500 has an SLC cache which increases with drive capacity. Consequently, the larger capacities are better able to sustain high sequential write speeds. The 250 GB version has 250MB of SLC cache, the 500 GB has 512 MB, the 1 TB has 1 GB and the 2 TB has 2 GB. Extended sustained write performance tests show that even though speed does drop off after the cache has been exhausted, it is still maintained at very respectable levels. The MX500’s five year warranty is in line with Samsung’s 850 Evo and exceeds it in terms of endurance (just 75 TBW for the 250 GB 850 Evo versus 100 TBW for the 250 GB MX500). It doesn’t quite match up to the Samsung’s 850 Evo’s performance (effective speed 8% slower), however at current prices it is about 20% cheaper, and on balance offers better value for money.

— The 860 Pro is Samsung’s latest consumer-grade SATA SSD flagship, superseding the popular, but now three years old, 850 Pro. Like the 850 Pro, the 860 Pro is based on Samsung’s proprietary and revolutionary (at the time), MLC V-NAND (3D). A 10% price premium over the 256 GB 850 Pro will purchase the 256 GB 860 Pro which has an impressive 16% faster effective speed. This is achieved via an updated controller (MJX) and 64 layers of V-NAND (versus 32 layers per the 850 Pro). The 860 Pro has sequential speeds of up to 540 MB/s which almost completely saturate its SATA 3.0 interface. These peak levels of performance are slightly higher, but still comparable to the peak performance of the 860 Evo before its SLC write cache (12 GB on the 250 GB Evo) is saturated, making the 860 Evo (at around 30% cheaper) a more economical choice for users who rarely write more than 12 GB at a time. There are also reliability improvements compared to the 850 generation with Samsung now offering a warranty of 300 TBW (terabytes written) for the 256 GB 860 Pro, compared to 150 TBW for the 256 GB 850 Pro. Thanks to higher density NAND, the 860 Pro is also available in a 4 TB variant, whereas previously 2 TB was the largest capacity for a Samsung SATA MLC SSD.

— The 860 Evo is the latest mainstream SATA SSD from Samsung. The 2.5-inch version of the 860 Evo will be available in several capacities ranging from 250 GB to a staggering 4TB. It’s also available in the slimmer M.2 and mSATA form factors. The 860 Evo demonstrates marginally reduced performance compared to its popular, but now three year old predecessor, the 850 Evo. In a head to head comparison the 860 looses by a very modest 6% in terms of effective speed. The 860 Evo is based on a refinement of Samsung’s consumer grade TLC V-NAND, this time featuring 256Gb and 512 Gb 64 layer V-NAND and it also features a new "MJX" controller. The 250 GB version can reach sequential write speeds of up to 520 MB/s, dropping to 300 MB/s once the SLC cache is exhausted (the 250 GB version has a 12 GB SLC write cache). Peak sequential read speeds of 560 MB/s are achievable across the different capacities. The 250GB version has a 512 MB LPDDR4 DRAM cache. All capacities have a five year warranty, but as a testament to the enhanced reliability of this new technology, the warrantied terabytes written (TBW) has doubled from 75 TBW to 150 TBW for the 250 GB 860 Evo.