Review: SanDisk Extreme PRO 480GB SATA SSD
SanDisk’s Most “Extreme” SSD Ever
When SanDisk first introduced the Extreme II SSD last year, it easily ranked as one of the best enthusiast SSDs on the market. Unlike many enthusiast SSDs which can reach top performance only in light workloads, the Extreme II is also capable of top, consistent performance even after heavy, extended use. At the time, this was a fairly new aspect of enthusiast SSD performance which was generally only a metric in the enterprise space.
Recently at Computex early last month, SanDisk unveiled the successor to the SanDisk Extreme II, the SanDisk Extreme PRO which we have the opportunity of reviewing today. Like the SanDisk Extreme II before it, the SanDisk Extreme PRO is designed for users such as media professionals, gamers, and PC enthusiasts who not only demand fast, but also consistent performance.
SanDisk Extreme PRO Specifications
|Model||Extreme PRO||Extreme PRO||Extreme PRO|
|Form Factor||7mm, 2.5″ SATA||7mm, 2.5″ SATA||7mm, 2.5″ SATA|
|Controller||Marvell 88SS9187||Marvell 88SS9187||Marvell 88SS9187|
|NAND||SanDisk 19nm eX2 ABL Toggle Mode MLC||SanDisk 19nm eX2 ABL Toggle Mode MLC||SanDisk 19nm eX2 ABL Toggle Mode MLC|
|Sequential Reads||550 MB/s||550 MB/s||550 MB/s|
|Sequential Writes||520 MB/s||515 MB/s||515 MB/s|
|4K Random Read||100,000 IOPS||100,000 IOPS||100,000 IOPS|
|4K Random Write||90,000 IOPS||90,000 IOPS||90,000 IOPS|
|Interface||SATA 3 6Gb/s||SATA 3 6Gb/s||SATA 3 6Gb/s|
|Endurance||>80 TBW||>80 TBW||>80 TBW|
|Warranty||10 Years||10 Years||10 Years|
The SanDisk Extreme PRO will come in only three capacities – 240GB, 480GB, and 960GB. It’s nice to see that capacities such as 120/128GB are finally being dropped from SSD lineups thanks to ever increasing die sizes, ever increasing dies per package, and ever decreasing prices. As far as internals go, the SanDisk Extreme PRO isn’t much different from the SanDisk Extreme II. In fact, it’s using the exact same Marvell 88SS9187 “Monet” controller as well as pretty much the exact same in-house proprietary 19nm eX2 ABL Toggle Mode MLC.
What’s different about the new SanDisk Extreme PRO however, is mostly a reworked firmware and an enhanced version of nCache, which SanDisk calls nCache PRO.
For those who aren’t familiar nCache from some of SanDisk’s previous SSDs, nCache is basically a repurposed portion of the main MLC storage which acts as a SLC cache. This SLC nCache is used to store mapping tables along with small write segments which is then later flushed to the main MLC flash storage.
By doing so, this provides two benefits. The first benefit is higher performance. As SLC is significantly faster than MLC, writes to the nCache would be a a lot faster than writes to the main MLC storage. This is pretty obvious. The second benefit is better data security. Without nCache, the mapping tables and small write segments would be stored in the volatile DRAM cache which would result in data loss in the event of a power failure. By using the non-volatile SLC cache to store mapping tables and small write segments, this problem is mostly avoided – the reason I say mostly is because SanDisk still employs the use of a DRAM cache in conjunction with nCache.
Since nCache is a proprietary technology, we’ve never really been given a whole lot of details regarding the actual changes between the old nCache and the new nCache PRO, but SanDisk did tell us that the capacity of nCache PRO is less than 1GB, similar to the older nCache implementations. Since the size of the cache is the same, my best guess is that nCache has been optimized to be more efficient although I doubt that there’ll be any massive performance improvements without significant increases to the size of the nCache.
Additionally, SanDisk is also doubling the warranty term on the drive, making it an industry leading 10 years – similar to the warranty we saw on the recently released Samsung 850 PRO. SanDisk is also rating the Extreme PRO at >80 TBW (Tera Bytes Written), which is slightly different than the hard and fast 80 TBW rating on the older Extreme II.
Let’s take a closer look at the drive.