SanDisk's Z400s is inferior to the products we compared it to. The drive serves up impressive notebook battery life, but that's one of its few bright spots. To be fair, in some of our other tests, the Z400s fares much better than I expected.
We recently learned that the Z400s is being validated by at least one major OEM, though it hasn't completed the process yet. We've been talking a lot about low-end SSDs displacing hard drives in tier-one PCs, so it'll be interesting to see if builders can roll DRAM-less solid-state storage into their designs before the holidays.
If we take this new class of SSD and generalize about their allure, it becomes clear that the upgrade market won't be swayed. OEMs won't be able to help but dip those three letters into gold for their marketing purpose. However, just because you see SSD on the spec sheet doesn't mean you're getting the drive you really want. As a storage reviewer, I'm a little biased. But the performance metrics show that these products are faster than hard drives and slower than the SSDs truly deserving of praise.
Price is a primary consideration in this segment. A while back, four 128GB Z400s could be purchased together for 25 cents per gigabyte. Sadly, that deal is no longer available. If that's what you pay, though, then you know OEMs are getting them even cheaper in volume. I would buy a notebook with this SSD installed, but I wouldn't pay a premium for it. Enthusiasts who value the snappy SSD experience we love at the high end will treat DRAM-less drives the same way they would a hard disk: they'd replace it.
That's not to say everyone who buys one of these in an OEM notebook will do the same thing. A DRAM-less SSD is better than a mechanical drive. But price parity will be part of the package. Just ask questions when you see a system advertised with an SSD inside to really understand what you're getting.
As a potential upgrade, the Z400s is a fairly poor prospect, largely because of its price. In terms of value, Samsung's 850 EVO just wrecks every other company's attempt to compete. With the 128GB Z400s at $45 and the 120GB 850 EVO going for $68, we have to recommend Samsung's offering. The 256GB-class comparison also favors the 850 EVO ($88 versus $80). The only way we can see this changing would be if you need to buy in volume. For upgrading a single PC, spend the extra $20 on Samsung, we say.