Samsung 840 Pro SSD review - Article

The Samsung 840 Pro series without TLC

Now before you go, huh what ? TLC (tender love 'n care) I do have to explain the introduction title. Samsung very recently released the new 840 series SSDs. The new 840 uses TLC NAND flash (TLC is short for triple level cell) cells whereas the PRO models (as tested today) still use the popular MLC NAND. TLC is short for triple level cell, but it’s simpler to state that each TLC NAND cell is able to hold three bits of data while MLC was only able to record two bits. A TLC NAND flash chip will hold 50% more data than an MLC NAND flash chip with the same number of cells. The increase in density however makes that NAND type a bit slower. In fact as such the 840 Pro series uses MLC NAND, and the more affordable basic 840 SSDs use TLC. With TLC NAND reportedly beings a good chunk slower and having less write cycles, really you might want to be on the lookout for the PRO models, as we'll test today.

We've been testing NAND Flash based storage ever since the very beginning. And it is surprising to see where we have gotten. The SSD market is fierce and crowded though and one brand quite popular in Europe now also has introduced a line of SSDs. 

While stability and safety of your data have become a number one priority for the manufacturers, the technology keeps advancing in a fast pace as it does, the performance numbers a good SSD offers these days are simply breathtaking. 450 to 500 MB/sec on SATA3 is the norm for a single controller based SSD.  Next to that the past year NAND flash memory (the storage memory used inside an SSD) has become much cheaper as well. Prices now roughly settle just under 1 USD per GB. That was two to threefold two years ago. As such SSD technology and NAND storage has gone mainstream. The market is huge, fierce and competitive, but it brought us where we are today ... nice volume SSDs at acceptable prices with very fast performance.

Not one test system in my lab has a HDD, everything runs on SSD while I receive and retrieve my bigger chunks of data from a NAS server here in the office. The benefits are performance, speed, low power consumption and no noise. You can say that I evangelize SSDs, yes Sir .. I am a fan.

So I'm happy to report that we can finally put a Samsung drive to the test. Samsung’s new 840 SSD Pro product line is powered by the company’s new MDX controller. The 3-core MDX controller this drive will be amongst the fastest we have ever tested.

As stated MLC NAND ICs are used opposed to TLC for the non pro models. Interesting to see is that Samsung applied a node shrink type of NAND, as Samsung moved to 21nm NAND manufacturing technology so here the density increases once more. 

IOPS numbers are now reaching the 90,000 ~ 100,000 mark. Overall for the 840 series performance has increased as well. Sequential reads for example speed went up from 520 MB/s (Samsung 830 SSD) to 540 MB/s for the 840 and the 840 Pro. Write performance went from 400 MB/s to 450 MB/s on the 840 Pro. 
 

Samsung 840 Pro SSD with 20nm NAND and the Samsung MDX controller