Samsung 845DC EVO Review (960GB) – Great Read Performance & Low Pricing

Samsung is today extending its enterprise offering with the release of the 845DC EVO.  They are aiming this release directly at those server and data center customers who are looking for a cost effective solution with great consistency and performance.

A little over a year ago, we took a look at the Samsung SM843, an enterprise SSD that competed in the still new read-focused enterprise SSD market.  At the time, the Samsung 840 Pro had been on the market for almost a year and was winning numerous awards along with critical acclaim.  Samsung took the 840 Pro architecture and created the SM843.  In our review, we loved that the high performance of the 840 Pro mostly carried over to the SM843.  We also like that it was a low-cost alternative to the SSDs from Intel and Micron.  The only thing that made us a little weary was the lack of power-loss protection (PLP).  For an enterprise SSD, even an entry-level drive, the lack of PLP seemed like an omission.

This time around, Samsung is looking to improve on the SM843 in every single way.

We weren’t really sure where Samsung was going to go with their enterprise products.  The 840 Pro is still around and kicking, but there hasn’t been a true follow-up in that class of high-end consumer SSDs.  Honestly, we didn’t think that the 840 EVO was a good candidate for the enterprise transition.  This is mostly because of the fact that the EVO used TLC NAND, which has a bad (unwarranted?) reputation for reduced endurance.

But, that is exactly the direction that Samsung took.  With the introduction of the 845DC EVO, Samsung is showing what it can do with 3bit MLC (TLC) NAND at an enterprise level.

SPECIFICATIONS

The 845DC EVO comes in 3 capacities: 240, 480 and 960GB.  We are primarily looking at the 960 version today.  Regardless of the capacity, the 845DC specifies some blistering read performance.  87K IOPS is a huge number that puts Samsung at the top of almost every enterprise SSD list.  Samsung did fix one of the wrongs of the SM843, which was the lack of power-loss protection.  The 845DC should have a level of protection during power loss that SM843 lacked.

Finally, the 845DC has a 2Mhr MTBF and a 5 year warranty that is becoming standard at an enterprise level, but is still beyond what any consumer SSD can offer.

INTERNAL COMPONENTS

The first thing you notice once you remove the outer case is the small number of NAND packages on the 845DC.  Each NAND package is 128GB, which consists of 8 die with a density of 16GB.  There are a total of 8 NAND packages on the 960GB model for a total of 1024GB.  Unlike the 840 EVO, the 845DC has a full sized circuit board.

The NAND packages, labeled K90KGY8SP7M-CCK0, appears be identical to the NAND that was used on the 840 EVO.  This 19nm Toggle 3bit MLC NAND, in part, allows for the high density that we see in this line.

The cache is a single 1GB Samsung DRAM package, which is typical for SSDs of this capacity.

The driving force behind the Samsung 845DC EVO is their MEX 3-Core ARM Cortex-R4 (400Mhz) controller which is 33% faster than its predecessor found on the SM843.  This newest controller should also deliver better performance and consistency.

This is exactly what the SM843 was missing.  Across the top of the circuit board we have multiple rows of capacitors.  In the event of sudden power loss, these capacitors will keep the drive going long enough to commit all data from the write cache to NAND.