Samsung’s SSD 850 Evo uses 3D V-NAND, the firm’s proprietary technology for vertically arranging flash memory cells. We’ve explained the advantages of V-NAND in the 850 Pro review on p52, and it clear that it adds considerably to the cost of SSD production. The 850 Evo aims for a lower price than the 850 Pro, but its prices aren’t the lowest around. The Crucial BX100 and OCZ Arc 100 are both more affordable, as is the Kingston SSDNow V300.
The 850 Evo notably uses 40nm threebits-per-cell (TLC) flash, as opposed to the 2-bit MLC of most SSDs, making it the first SSD to contain both TLC and 3D NAND. TLC often leads to reduced performance and endurance but, thanks to the magic of 3D V-NAND, some firmware optimisation and an SLC cache called TurboWrite, the 850 Evo drives still run fantastically well.
With TurboWrite, a small portion of the available capacity is treated as 1-bit-per-cell SLC flash, which offers higher performance when used as a cache for the main TLC flash. As long as you’re writing to the SLC cache, performance will remain as high as you’d expect from any top-end MLC-based SSD, but once you’ve gone over that with a write command, the speed will drop to TLC-level performance until the 850 Evo has time to write the data back to the TLC portion of the drive. There’s 3GB of SLC cache in the 250GB model, 6GB in the 500GB and 12GB in the 1TB. In everyday use, it’s unlikely you’ll perform many writes that go over this limit, though, and we didn’t encounter it in our tests.
Hardware encryption with AES 256-bit and TGC Opal standards are supported, as is the low-power DEVSLP mode. As with the 850 Pro, the 850 Evo also supports Samsung’s Rapid RAM cache, as part of the Magician software.
Synthetic performance results are excellent, with the 850 Evo breaking the 530MB/sec barrier in sequential reads, and jostling for position with the 850 Pro for sequential writes.
In real-world tests, the 850 Evo once again fares well. The 1TB model achieved the best Battlefield 3 trace result, the second best PCMark 7 result and was close to the top in the Microsoft Word and Photoshop Heavy tests too. The 250GB and 500GB capacities weren’t quite as good, but since the differences between these results are so small, there’s no reason for complaint.
Conclusion
The 850 Evo brings the benefit of 3D V-NAND to a wider audience due to better affordability than the 850 Pro. It performs well in synthetic tests, brilliantly in real-world tests and is competitively priced. Its SLC cache is large enough not to get in the way of performance, and the 850 Evo supports encryption and low-power consumption features, along with the extras offered by Samsung’s Magician software, such as Rapid mode. This mix of affordability, performance and features makes for a winning combination.
VERDICT
A winning combination of reasonable pricing, plenty of features and great performance.
OVERALL SCORE
SAMSUNG 850 EVO 250GB – 90
SAMSUNG 850 EVO 500GB – 93
SAMSUNG 850 EVO 1TB – 91
