Finally! Crucial has released their first NVMe M.2 SSD. While the enthusiast in me was hoping for a super-high-end MLC-based drive that takes on the Samsung 970 Pro, the P1 is nothing to sneeze at. It is the second QLC-flash-based drive to be released (Intel 660p was the first). QLC is the next generation in flash storage technology, storing four bits per flash cell instead of three on TLC. This reduces manufacturing cost per Gigabyte significantly—in theory by 25%. Of course, this isn't without its drawbacks. QLC has lower endurance and lower write speeds; more on that later.

With read speeds of over 3 GB/s and writes in the 1.6 GB/s range, our synthetic testing shows great results. IOPS are also high, reaching 360,000 IOPS for reads and 250K for writes. Mixed read/writes are significantly lower than for TLC competitors, though; we're not exactly sure why and have asked Crucial for additional insight into this.

In our real-life performance testing, the Crucial P1 does very well, reaching an average performance result similar to the Intel 760p, slightly behind the Samsung 970 EVO. Our price/performance favorite, the ADATA SX8200, ends up 7% faster. Compared to older SATA SSDs, the performance uplift is around 10%.

QLC's biggest weakness is the low write performance, which is why Crucial added pseudo-SLC caching to their SSD. As long as there is space left in the pSLC buffer, writes fly, with a constant 1,600 MB/s. This keeps up for a surprisingly long time; in our testing, we had to write data at maximum speed for almost 10 minutes, 120 GB in total, until the write buffer was exhausted. Beyond that, write speeds fell of a cliff, reaching only a meager 150 MB/s. It's good to see such a large pSLC cache size on the P1, bigger than on most SSDs we tested before. It means that the cache will be able to soak up all but the biggest write bursts. It's highly unlikely you'll ever write that much data anyway, except maybe during a disk image restore, and even then your source is unlikely to provide 1.6 GB/s. Once the drive is idle, the SLC buffer gets flushed to QLC, which quickly restores full write performance.

Thermal throttling is an issue for nearly all M.2 NVMe SSDs, and the Crucial P1 is no exception. Not cooled and fully loaded, it will heat up quickly and start throttling after a bit more than a minute at full load. Now, don't get scared. In that time, the drive processes almost 100 GB of data. Again, highly unlikely in a consumer scenario. Still, I would have wished for a higher temperature limit and a more graceful drop in performance during thermal throttle. Samsung, for example, has implemented that very well.

Crucial is giving five years of warranty for the P1, which is great and matches competitors. Endurance is lower than for TLC drives with "only" 200 TBW for our 1 TB version, but that should still be enough for all consumers. 200 TB is over 100 GB written per day over five years. Highly unlikely you're writing that much data. If you do, you're probably not a consumer and might want to consider server-class SSDs.

Crucial's P1 SSD is currently priced at $220 for the reviewed 1 TB version, which isn't bad at all. 1 TB M.2 NVMe PCIe x4 drives start at around $215, so the P1 is definitely an option in that price range. However, given the cost-improvement promises of QLC, I have no doubt Crucial could price the P1 much cheaper and is just testing the waters for now because of the lack of competition. Right now, the most affordable 1 TB-class SSD is the ADATA SX8200 ($215), which is our top pick when it comes to price/performance. Compared to competing drives like the Samsung 970 EVO ($280) and Intel 760p ($290), I'd pick the Crucial P1 any day because of the significant cost savings. If only price per GB matters to you and speeds are secondary, the best option is the Crucial MX500, which costs around $160 at the moment.