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Technical Specifications
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Although they aren't groundbreaking, the 2TB 850 Pro and EVO drives do add some excitement to both line-ups. For the most part, Samsung simply added twice as much NAND to get to 2TB. It also doubled the on-board cache and upgraded it to low-power DDR3 (LPDDR3) for the largest capacity size. The DDR3 runs at a higher clock speed and uses less power than the older DDR2. Both increases are offset by the larger table maps (speed) and more NAND dies (power).
A new controller was necessary to support twice as many CE paths to the 32-layer V-NAND flash. This does increase interleaving, and you will see the impact of this in the performance results, even if officially, Samsung specs the 850 Pro 2TB and 850 EVO 2TB for the same performance as its 1TB models.
The 2TB capacity point really favors the 850 EVO more than the Pro. You're going to see a huge price gap right off the bat, but there's more to the story than just a $200 difference. The Samsung 850 EVO 2TB uses TurboWrite technology, a layer of emulated SLC flash that acts as a buffer for data writes. With more flash on the drive, Samsung was able to increase the amount reserved for TurboWrite. We had to push the drive really hard to figure out where the cache ended and TLC write performance began. Outside of working with massive video files in a workstation environment, you'll probably never observe writes at TLC speeds.
Both new products support Self-Encrypting Drive (SED) technology like existing models. We hope that many power users will take advantage of eDrive, Microsoft's Windows-based IEEE-1667 encryption technology, but TCG Opal is supported as well.
Samsung's documentation shows the 2TB models using slightly more power under different conditions than the 1TB versions. You may be tempted to interpret that as less notebook battery life, but in practice, that's not the case. The increased interleaving, as well as the larger TurboWrite area (850 EVO-only) yield more time away from a wall socket, actually. We'll go into more depth on this shortly.
