SanDisk Extreme PRO 480 GB review: what it is, why it matters
The SanDisk Extreme PRO builds on the already excellent Extreme II SSD, adding a larger DRAM cache and revised firmware. Like the previous Extreme II it replaces, the Extreme PRO relies on the Marvell 88SS9187 controller running SanDisk’s own custom firmware. This combination is backed with a generous 1 GB of DDR3 memory for the largest 960 GB capacity model, and also the 480 GB size that we tested. The main flash chips are again SanDisk’s own, the second generation of its 19 nm-process NAND. And now sitting between the volatile dynamic RAM cache and the more permanent NAND storage chips is a new version of the non-volatile cache that SanDisk now calls nCache Pro. SanDisk’s nCache Pro is based on fast and resilient single-layer cell (SLC) flash and acts as a half-way house for saving up smaller chunks of data at high speed before consolidating and then flushing them out to the main MLC flash banks. Three capacities of drive are again offered, only this time they’ve been moved up in size by a factor of two – so the entry-level SSD is now 240 GB rather than 120 GB, and a 960 GB is the new large. Only the traditional 2.5-inch SATA form factor is offered at present, in the now-standard 7 mm height, so no mSATA or M.2 SATA alternatives. To maintain and oversee this SanDisk SSD the company offers its SSD Dashboard program for Windows. We found this to be simple yet well-featured, clearly laid out and able to secure erase, sanitize and TRIM the drive on demand. Firmware updates are easily executed here too. One feature will not work though, Crypto Erase, since the Extreme PRO does not include any on-board hardware encryption. SSD Dashboard just needs a tick-box setting to switch off in-line advertisements, since we use the program to operate the SSD, not shop for more SanDisk products and those of third parties. SanDisk stands behind its top consumer SSD by being the first company to offer a 10-year guarantee. Whether there will be many PCs supporting SATA Revision 3.0 drives in another decade is another question. See our group test: What’s the best SSD?
SanDisk Extreme PRO 480 GB review: cost, value
SanDisk Extreme PRO 480 GB review: Performance
The SanDisk Extreme PRO easily clears the low hurdle of high sequential speeds as measured by ATTO Disk Benchmark, with 556 MB/s reads and 525 MB/s sequential writes. It also pulls off a similar feat with CrystalDiskMark, which is usually a tougher judge here, with 511 MB/s reads and 478 MB/s writes; mirrored closely in speed when using random data here too. When presented with 4 kB single-threaded datastreams it kept up the pace, just behind the Samsung with 32 MB/s 4 kB random reads and 88 MB/s random writes. As the queue depth increased to 32 threads the SanDisk remained unfazed, ending in a read IOPS figure just shy of the nominal watershed of 100,000 IOPS, and write performance at around 79 k IOPS.
