While Samsung's SSD 850 Pro turned in superb results when we reviewed it in late June, we couldn't quite crown it the performance king without having benched SanDisk's new flagship. Released nearly a month before the 850 Pro, SanDisk's Extreme Pro is the successor to the venerable Extreme II, which was among the best SSDs of its generation in terms of performance and reliability.
Like Samsung's 850 Pro, SanDisk's flagship SSD is aimed at gamers, enthusiasts and professionals who demand the highest real-world performance, so it's no surprise to see them trading blows on pricing. As of writing, the 256GB SSD 850 Pro beats the 240GB Extreme Pro at roughly 10 cents cheaper per gigabyte, the 480GB Extreme Pro and 512GB SSD 850 Pro both cost around 77 cent per gig while the 960GB Extreme Pro is cheaper than the 1TB SSD 850 Pro by around $100 or 7 cents a gig.
Those prices are pretty evenly matched and although it's significantly less than you would have paid for a high-end drive a few years ago, budget models that have continued to make the most headway. Crucial's MX100 512GB costs nearly half of both the Samsung SSD 850 Pro 512GB and SanDisk Extreme Pro at just $215 or 42c per gigabyte, so that is worth keeping in mind when analyzing the benchmark data.
SanDisk Extreme Pro
The SanDisk Extreme Pro series is shipping in capacities of 240GB, 480GB and 960GB, all of which have a slim 2.5" design, measuring 7.0mm x 69.85mm x 100.5 mm. Power consumption is very low compared to conventional hard drives, as the Extreme Pro uses a maximum of 3.6 watts when writing and 2.9 watts when reading.
The 240GB model has read and write speeds of 550MB/s and 520MB/s, while the 480GB version (which we have for review) boasts a similar read/write rating, though surprisingly the write throughput has been downgraded to 515MB/s -- same for the 960GB model as well.
Once formatted in Windows, the original 480GB is converted to 447GiB, though Windows shows this as 447GB, so it seems like 7% of the original capacity has been lost. With a current retail price of $370, the Extreme II 480GB costs $0.77 per gigabyte, a reasonable value for a high-performance SSD.
The Extreme Pro is really a new revision of the Extreme II rather than an entirely new product. SanDisk is sticking with the proven formula for now, giving the Extreme Pro the same controller as its predecessor. Rather SanDisk has opted to refine the firmware while using its own second generation 64Gbit 19nm MLC (same as Toshiba's A19nm).
The Marvell 88SS9187 controller (codenamed "Monet") features a dual-core Marvell 88FR102 V5 CPU with shared DTCM and ITCM SRAM. The controller supports up to a 1GB DDR3-1600 memory buffer though this is only taken advantage of on the larger two models while the 240GB model receives a 512MB buffer. In the case of the 480GB model, that's four times the buffer of its predecessor.
All Extreme Pro models are loaded with 1Ynm eX2 ABL MLC toggle flash memory. Our review sample has eight 64GB SanDisk 05445 064G ICs for a capacity of 512GB. That said, it's advertised as a 480GB model, as 12.7% of the original capacity is used for over-provisioning.
The nCache technology seen in the previous models makes a comeback in the Extreme Pro, though it has been updated and is now called nCache Pro. The changes seem minor as far as we can tell. Previously nCache has used firmware and NAND mapping table caching.
nCache Pro is more optimized for user data caching but with less than 1GB of SLC caching memory it is probably being used more as a buffer than a serious performance enhancing feature. The Extreme Pro 480GB does feature a 1GB DRAM cache as well, but the SLC cache is used for writes smaller than 4K.
The Extreme Pro is qualified to deliver 80 terabytes of written data with a MTBF of two million hours, meaning roughly 22GB can be written to the Extreme Pro over a 10-year period. That's a heck of a lot and regardless of its MTBF, the Extreme Pro carries a respectable ten-year warranty.
It's worth noting that unlike older SSDs, such as the OCZ Vertex 4, the SanDisk Extreme Pro lacks any sort of AES encryption or eDrive support, though hardware encryption support was absent from the previous Extreme II model as well.