While SanDisk’s Extreme Pro range (see opposite) aims for the top end of the market, it’s cheaper Ultra II series caters for the mid-level segment. All SSD manufacturers seem to be employing a similar strategy for their cheaper drives: shave off a few features, along with some performance via cut-down controllers that are cheaper to build, enabling them to cut a great deal off pricing.
And as with Crucial’s BX100 range, hardware encryption has been dropped completely, with the warranty cut to just three years. The Ultra II in four capacities: 120GB, 240GB, 480GB and 960GB, with the 240GB model on test in this Labs.
Two separate controllers are employed across the Ultra II fleet, Marvell’s 4-channel 88SS9190 in the 120GB and 240GB models, and Marvell’s 8-channel SS889189 in the 480GB and 960GB.
SanDisk mitigates the performance and endurance issues of TLC flash memory in a similar way to other firms, with a portion of the drive’s capacity reserved for use as SLC flash, which it calls nCache 2.0. Accordingly, 5GB of the Ultra II’s capacity is reserved in the 120GB model, and this allocation doubles as the capacity increases: 10GB in the 240GB model, 20GB is reserved for the 480GB and 40GB in the 960GB.
One technical difference between SanDisk’s system and those of other manufacturers is the way transfers are made between SLC and TLC storage with nCache 2.0. Usually, such a system reads data from the SLC storage into an SSD’s DRAM cache, then writes it to the TLC portion of the drive. With nCache, this work is all done on the chip itself, without having to access the drive’s DRAM, leading to vastly reduced latency times and better performance.
With a retail price of almost £83, and a formatted capacity of 224GB, the Ultra II costs 37p per gigabyte of storage, which isn’t quite as good value as Crucial’s 250GB BX100 (32p) or Samsung’s SSD 850 EVO (36p), but it’s still reasonable.
From the synthetic benchmark results, Ultra II sits slap bang in the middle of most of the charts, with very promising sequential read results in CrystalDiskMark of 545.3MB/ sec, with write speeds down to 464MB/sec in AS SSD – a small drop but not a terrible worry. In random read and write tests, the Ultra II storms ahead of pricier drives such as Intel’s 730 too, and constantly puts Crucial’s BX100 to shame. However, the measured IOPS is worryingly low. The Ultra II’s result of 19,647 is the lowest of all the SSDs we tested, and around half the result achieved by the Samsung 850 Evo.
It’s the real-world trace results that really count, though, and the Ultra II does fine here. Although its results are near the bottom in the Photoshop Heavy test, the difference in scores between the topperforming Intel SSD 730 and the Ultra 2 is seven seconds, or roughly 2 per cent. Not exactly a massive difference. It’s even less noticeable in the Microsoft Word trace, where the difference is 0.5 seconds, with the bulk of all the drives being just 0.2 or 0.3 seconds ahead – hardly anything to complain about. The Ultra II also comes second best in the BootRacer test, loading Windows in a nifty 10.78 seconds.
Conclusion
The Ultra II fares well in real-world performance tests, and does a reasonably good job in synthetic tests too. It’s a good drive and not too expensive. But ultimately it falls into a difficult spot between the more affordable Crucial BX100 and Samsung’s better-performing SSD 850 Evo, and both drives offer a better balance of performance and value for money.
VERDICT
An affordable drive with good performance, but fierce competition from Samsung and Crucial puts it in a tough spot.
Overall Score – 84
