Low cost per gigabyte, and Marvell
SS889175 controllers
SanDisk is clearly a fan of Marvell
controllers, with the SS889187 chip used in the firm’s Extreme II drive , but for its Ultra Plus and X110 models, the firm has turned to the
Marvell SS889175.
SanDisk X110 256GB $206.19 inc VAT
This controller is the sequel to the
9174, which was a big hit in older SSDs such as the Plextor M3 and Intel 510
Series, and it’s designed to improve on its predecessor with lower power
consumption, thanks to a quartet of independent NAND channels. It also allows
to direct access to the firmware, so SanDisk has been able to craft its own
firmware for the Ultra Plus 256GB.
Like the Extreme II, SanDisk has
deployed 19nm MLC NAND inside this drive, and it also has the nCache system
that we saw in the Extreme II. This feature is designed to replicate SLC
(single level cell) performance across a small section of the SSD’s NAND and,
in theory, improve small file write speeds. As with other SanDisk drives, the
Ultra Plus uses the slimmer 7mm form factor, and there’s a three-year warranty
too, although plenty of other drives have five-year deals now.
SanDisk Ultra Plus 256GB $197.87
The third SanDisk drive in this Labs,
the X110, has recently made the move from the business market to the consumer
side, and it also relies on the Marvell SS889175 controller. It uses the same
19nm NAND too, and the same nCache system. However, the X110 has the added
benefit of read error protection that can repair faults with no performance
overhead, as well as thermal throttling to prevent overheating, although
admittedly, this isn’t an issue we’ve ever encountered with SSDs – it’s only
ever likely to be an issue in crowded server racks. Like the Ultra Plus, the
X110 also has a threeyear warranty.
It’s no surprise that two drives with
similar specifications weren’t too far away from each other in benchmarks –
throughout our theoretical tests they were often next to each other in the
results tables.
However, while nCache may be designed
to improve small file write performance, these two drives sat towards the
bottom of our results tables in both of AS SSD’s applicable tests; they managed
96MB/sec in the 4KB random write test, which is almost 20MB/sec behind the
leading drive, and they were around 125MB/sec behind the best drives in the
64-queue-depth random write test too. The Ultra Plus and X110 were consistently
better when reading small files, though, and were mid-table in the sequential
benchmarks.
SanDisk Ultra Plus
We spotted the same pattern in
CrystalDiskMark; these drives might have a system designed to impact small file
writes, but in these benchmarks, both drives performed disappointingly. In the
32-queuedepth random write benchmark, they were bottom of the pile. Conversely,
sequential and 4KB random reads were a little better.
Meanwhile, the X110 returned a boot
time of 11.85 seconds, which is one of the best on test, but neither drive
impressed in the rest of our real-world benchmarks. They were both in the
bottom three in PCMark 7’s application boot run, and stayed in the bottom third
of this month’s drives in the gaming test. The situation didn’t improve in
Iometer, where these drives were bottom – and scores of around 16,400 were a
long way behind the 22,621 scored by the Samsung 840 Evo 250GB, which was the
next-best drive.
Conclusion
Both these drives offer reasonable
value for money, with the Ultra Plus costing 50p per gigabyte and the X110
costing 2p more. That’s in the top half of our results table, but that’s the
only area where these drives impress. There’s plenty of competition around the
256GB mark, and the Samsung 840 Evo is much faster and only a few pence per
gigabyte more expensive.
Verdict
Reasonable all-rounders, but that isn’t
enough to cut it in the SSD market any more.
