SanDisk Extreme II SSD Review (240GB) – SanDisk Finds That Sweet Spot and Hits a Home Run

In baseball, there is a ‘sweet spot’ on the bat that everyone strives to hit when they strike the ball.

It is the spot that home runs are made of and finding it means that the baseball will rebound  with velocity never seen through contact with any other part of the bat. If the performance of the new SanDisk Extreme II SSD is any indication, SanDisk has just found that spot in SATA 3 performance.

The new SanDisk Extreme II SATA 3 solid state drive is SanDisk’s second generation of the Extreme family and, in this move, they have moved SandForce for Marvell.  Many will wonder if they chose wisely considering the obvious performance curve between the two, but the new Marvell controller has a definite feature that suits SanDisk very well.  It allows SanDisk’s in-house engineering team to create and fine tune their own firmware, thus creating the challenge of a higher performance. As we spoke of at Computex a few weeks back, this trend seems to be growing.

 Firmware isn’t the only key to this SSDs success as SanDisk now supports its own proprietary advanced flash management through tiered caching.  It seems that SanDisk picked up on something that we happened upon a few years back, and that is that small 4K blocks are accessed more than any other disk access size. For this, SanDisk has created nCache.

Without getting too complicated, nCache dedicates a very small portion of each NAND module to a ‘virtual’ SLC cache where small 4K writes accumulate.  When called, these 4K files are flushed at a speed much higher than they might normally be. Does it work?  Lets watch the benchmarks closely and then revisit this in our report summary.

The SanDisk Extreme II SSD is a SATA 3 SSD fully backwards compatible with SATA 2, comes in capacities of 120, 240 and 480GB, and has a standard 5 year warranty which is plus 2 years from the previous generation.  Performance is very surprising for a Marvell controller and speaks to read and write disk transfer speeds of 550 and 510MB/s, consecutively, with an IOPS high of 95,000.

Pricing for the Extreme II SSD is below $1/GB for all capacities and can be found at Amazon at $116.99 (120GB), $224.99 (240GB) and $456.20 (480GB), which will make this SSD extremely competitive. The Extreme II is TRIM and SMART compliant, is rated at 80TBW endurance and has a 7mm ultra form factor with a black plastic casing protecting the interior components.

Looking at the printed circuit board (PCB), we have the Marvell 88SS9187-BLD2 ‘Monet’ controller, Samsung 256MB DDR3-1600 DRAM cache below the controller and eight modules of SanDisk 19nm Toggle Mode eX2 ABL MLC 3K P/E cycle NAND flash memory.  Each module is 32GB in size for a total of 256GB RAW capacity, however, 7% over provisioning reduces this to the advertised capacity of 240GB.  Formatting the drive then leaves the user with 224GB of available disk (or rather SSD) space.