More capacity for less cash. But at what cost? That\u2019s the question for the new Crucial P3 Plus M.2 SSD, tested here in its 2TB configuration. It uses QLC flash memory to offer increased storage space at a conspicuously low cost, in this case around $179 (\u00a3205) for this 2TB drive at the time of this review. But is there a different price to be paid here?<\/p>\n
In simple terms, the answer is yes. The Crucial P3 Plus uses parent company Micron\u2019s latest 176-layer QLC NAND chips. QLC stands for quad-level cell and indicates four bits of storage per memory cell. That\u2019s one more than the TLC or triple-level cell flash memory typically used in premium, high-performance SSDs.<\/p>\n
Now, it\u2019s well established that as cell-level bit densities increase, both performance and endurance take a hit. But it\u2019s worth remembering roughly why. In simple terms, the complexity of reading and writing to a QLC cell is double that of a TLC cell. And that means it takes longer. Much longer. There\u2019s the performance hit.<\/p>\n
As for endurance, well, it comes down to the fact that every time a given cell is written to, it slightly wears out the oxide layer required to store the charge that in turn represents the bits\u2014the zeroes and ones\u2014that compose the actual data. And more bits per cell means that each cell is written to more frequently and thus wears out more rapidly. Hold all those thoughts.<\/p>\n
Available in 500GB, 1TB, 2TB, and 4TB capacities, indications that the new Crucial P3 Plus is a value-orientated product go further than merely the choice of flash chips. In conspicuous contrast to Crucial\u2019s more expensive SSDs, which use the brand\u2019s own controller chips, the P3 Plus is fitted out with the Phison PS5021-E21T.\u00a0<\/p>\n
The Phison E21T is basically a budget PCIe 4.0 controller, offering just four memory channels to the competition’s eight. It\u2019s also a so-called DRAM-less chip and thus doesn\u2019t support dedicated DDR cache memory. Instead, system memory performs the job of providing primary caching.<\/p>\n
\u200b\u200bCapacity: <\/strong>2TB Speaking of cache, one of the most important elements of any QLC drive is SLC cache provisioning\u2014or the proportion of the drive that can be allocated to run in much speedier SLC mode. In this case, it\u2019s around 20% of the available free space on the drive. As the drive fills, then, the amount of SLC cache available will shrink. But the main point is that QLC tech tends to make sense on larger drives where SLC provisioning can be fairly generous. Even half full, this drive is large enough that you should still get a few 100 GB of high-performance SLC cache, which is decent.<\/p>\n Anyway, for the record Micron says its latest 176-layer QLC chips are around 25% quicker than its outgoing 128-layer QLC memory. If that sounds like a nice speed bump, Crucial says this 2TB model is good for 5,000MB\/s reads and 4,200MB\/s writes, which is obviously a fair chunk behind typical TLC-based drives. Crucial doesn\u2019t even bother to quote IOPS numbers. Still, the P3 Plus does come with Crucial\u2019s usual five-year warranty and 44TB of rated write endurance.<\/p>\n Symptomatic of the impact of QLC memory, that latter figure is barely better than one-third the endurance offered by a premium TLC-powered 2TB drive like the WD Black SN850<\/a>. Of course, it\u2019s absolutes and not comparisons that matter. Is 440TB enough? It adds up to 240GB each day, every day for five years. Plenty for all but the most demanding users, then.<\/p>\n
\nController:<\/strong> Phison PS5021-E21T
\nProtocol:<\/strong> NVMe
\nNAND:<\/strong> Micron 176-layer QLC
\nInterface:<\/strong> M.2 PCIe 4.0 x4
\nForm factor:<\/strong> M.2 2280
\nRated seq. read: <\/strong>5,000MB\/s
\nRated seq. write: <\/strong>4,200MB\/s
\nWarranty: <\/strong>5 years
\nPrice:<\/strong> $179<\/a> | \u00a3205<\/a><\/p>\n<\/div>\n<\/div>\n