It’s a very good performer until it runs out of cache.

I regularly end bargain TLC SSD reviews with the advice “Don’t buy it unless it’s a lot cheaper than the competition.” Until Crucial’s P1, no drive ever met that criteria. But the 17 cents per GB that the 1TB version will set you back is a good 8 cents cheaper than most of the competition. And, while it’s no blazing-fast Samsung 970  Pro, you don’t give up a ton of performance unless you regularly write 50GB (less with smaller capacities) or more. If you do, move along to another review.
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https://www.pcworld.com/article/3337244/crucial-p1-nvme-ssd-review.html