Review: Samsung 850 EVO 500GB SSD
Reviewed by: Wendy Robertson
Provided by: Samsung
Firmware version: EMT01B6Q
Let's first step back a few years, to when SSDs first started to appear. They were very expensive, low capacity affairs. Sequential speeds were faster than HDDs, but not by much. Access times were much faster than HDDs, and of course small file random performance also was, in general, much better than any HDD could achieve.
Samsung was one of the first manufacturers to introduce an SSD, although this largely went unnoticed in Europe and North America. Things really started to take off for Samsung when they introduced the 830 series of SSDs a few years ago. Since the 830 series, Samsung has gone from strength to strength with the 840 Pro, and the 840 EVO series of SSDs. Not only were they top performers, they were also very affordable.
It's no secret that Samsung has been working on a new type of NAND, dispensing with the 'planar' arrangement and the 'charge pump device' (CPD), by moving to a 3D vertical stacking cylindrical cell arrangement (V-NAND) where the cells are stacked vertically, with up to 32 layers, allowing a much higher density. In V-NAND, the CPD is also gone, being replaced by a Charge Trap Flash (CTF). A CPD stores the charge in a semiconductor where imperfections in the material can cause electrons to leak, and thus reduce NAND endurance. A CTF stores the charge in the isolating layer, where leakage is not a problem. A CTF also requires much less voltage to store the charge, so as an added benefit, V-NAND requires much less energy to store the charge.
Moving to a vertical cell stacking arrangement rather than the planar design also has a huge advantage. Because stacking cells vertically takes up less space, it allowed Samsung to take a step back in the cell node size, so instead of shrinking the current 19nm node size, Samsung has been able to use a larger node size, most likely around 30nm. Increasing the node size means better endurance. Couple the new CTF method of storing the charge with the increased node size, and Samsung estimates that V-NAND could have as much as ten times the endurance of NAND based on the 19nm planar design.
Another advantage of using a larger node size is NAND page programming times are substantially reduced. Typically, 19nm planar NAND takes around twice the time to program a NAND page compared to 30nm 3D V-NAND. The end result is you get higher performance which is much more sustainable.
Okay, that's enough of the technical stuff, so let's get to the point of this article. Allow me to introduce the first consumer grade SSD to implement 3bits per cell (TLC) 3D V-NAND, the Samsung 850 EVO range of SSDs. The 850 EVO range of SSDs covers 120GB, 250GB, 500GB, and 1TB capacities. The 850 EVO SSD that Samsung very kindly provided for review is the 500GB version.
The Samsung 850 EVO is squarely aimed at the budget minded consumer.
One should keep in mind that the review Samsung 850 EVO SSD that I received was a pre-production model, with pre-production firmware, and the final production 850 EVO SSD may not behave exactly as the pre-production sample that I am featuring in this article.
Samsung company information
Samsung should need no introduction, but those of you who would like to find out more about Samsung, can do so at their website.
So let's find out how this new SSD performs in our range of tests.
The Samsung 850 EVO 500GB SSD
Now it’s time to take a look at the drive itself and what it came shipped with.
The review sample I received was a bare drive. Included in the package was the Samsung 850 EVO SSD, a software DVD, installation instructions, and warranty information.
Now let's head to the next page, where we look in more detail at the Samsung 850 EVO 500GB SSD.....