But the affordability comes with potentially deal-breaking catches. The P1 can’t handle heavy loads and has relatively low endurance. Thus, heavy users or those wanting to put a lot of data on it quickly should steer away.
On the other hand, if you’re a casual user, the P1 can be an excellent entry-level NVMe drive.
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Crucial P1: First QLC NVMe SSD
Not only the P1 is Micron’s first NMVe SSD, but it’s also the first that uses its quad-level cell (QLC) NAND flash memory as the storage space.
Initially, SSDs use single-layer-cell (SLC) of NAND flash memory which stores only a single bit per cell. This type of memory is super-fast and reliable but expensive. As a result, nowadays SLC is available just in enterprise SSDs.
To make consumer-grade SSDs more affordable, storage vendors have moved on to MLC (two bits per cell), then TLC (three bits per cell). And now the P1’s QLC NAND stores four bits per cell.
This high-density level means you can store more data on the same piece of a silicon wafer and drive the cost down. But in return, the SSD’s performance and its endurance — the amount of data you can write on the drive before you can’t anymore — can take a beating. And that’s the case of the P1.
Crucial P1: Hardware specifications
|Design||M.2 2280 S3 (Single-Sided)||M.2 2280 D2 (Double-Sided)|
|Interface||PCIe 3.0 x4||PCIe 3.0 x4||PCIe 3.0 x4|
|NVMe version||MVMe 1.3||MVMe 1.3||MVMe 1.3|
|Controller||Silicon Motion SM2263EN||Silicon Motion SM2263EN||Silicon Motion SM2263EN|
|NAND Flash||Micron 64L 3D QLC||Micron 64L 3D QLC||Micron 64L 3D QLC|
|DRAM||512MB DDR3||1GB DDR3||2GB DDR3|
|Sequential Read||1,900 MB/s||2,000 MB/s||2,000 MB/s|
|Sequential Write||950 MB/s||1,700 MB/s||1,750 MB/s|
|Random Read QD1||90,000 IOPS||170,000 IOPS||250,000 IOPS|
|Random Write QD1||220,000 IOPS||240,000 IOPS||250,000 IOPS|
|Endurance (Terabytes Written)||100 TBW||200 TBW||400 TBW|
|Warranty||5 Years||5 Years||5 Years|
Relatively low endurance
The P1 is available in 500GB and 1000GB that has the endurance ratings of 100 terabyte written (TBW) and 200TBW, respectively. (The 2000GB version will be available later this year and will have the endurance of 400TBW). That’s six times less endurance than the Samsung 970 Evo, which uses MLC NAND.
Also in my testing, despite having a small amount of expensive SLC NAND as a cache, the P1 delivered a mixed performance. (More below). What’s more, the drive doesn’t feature hardware encryption, either, so it’s not suitable for business applications.
Crucial P1: Detail photos
The P1 is inferior to other non-QLC NVMe SSDs. However, for most consumers, its shortcomings — at least some of them — might not matter much.
Take the endurance, for example, if you write 50 GB — that’s two Blu-ray discs worth of data — on a 1000GB P1 per day and every day, that’d still take you more than five years to wear out its endurance. Since most of us write a lot less than that per day, the drive’s low endurance rating is not a big deal.
What you should care about, however, is the performance and the P1 proved to be a compelling case in my tests.
Crucial P1: Wild performance
The P1 is the first drive I’ve worked with that showed huge performance degradation depending on how much you want to write to it continuously.
Indeed, generally, if you’re going to write about 130GB or less of data to the drive at a time, you’ll have the performance on par with other NVMe SSDs.
For standard copy tests, I used 100GB of data, and the P1 did quite well, as shown in the chart below. It’s not the fastest among NVMe peers by any stretch of the imagination, but still many times faster than even the speediest SATA SSDs.
However, when I wrote more than 130GB to the drive, starting with gigabyte number 131 or so, its performance dropped significantly — some ten folds — to just some 100MB/s. And then its speed continued to get even slower, to a crawling 50MB/s at some point, until the end of the copy job.
I also noted that the amount of data I could copy at fast speed varied. It got progressively smaller the longer I used the computer.
Specifically, at a fresh boot, I got the 130GB pass. After having used the computer for a while running everyday tasks, or after a light copy job, I could only get 100GB or 50GB, or even less, at fast speed before the performance degradation occurred.
The reason likely is during heavy loads, the drive runs out of the cache and what you have left is its true QLC NAND performance. The P1 only performs well when it can use its cache, which is limited. In a way, this drive is like a sprinter and not a marathoner. It needs a serious break after a short dash.
But don’t get too disappointed! In daily usage, without the intention to stress the drive, I didn’t notice the performance issue. The test computer still booted fast (taking just a few seconds), and most applications launched quickly.
Overall, in my experience, simple everyday tasks, like emailing, web-surfing, even media streaming, don’t push P1 past its performance degradation threshold.
Crucial P1's Rating
Fast performance for casual computing
Significant performance degradation during heavy or prolonged write operations
Relatively low endurance
No hardware encryption
Thanks to the pricing, the Crucial P1 is enticing to those wanting to upgrade to NVMe. And indeed, if you’re a light user, you’ll be happy with it.
However, due to the lack of the ability to handle heavy loads and extended operations with persistently fast performance, the drive has unpleasant surprises for heavy users.