How much are you writing to those drives? Have you tried any drives that will extend their pseudo-SLC cache across the entire space, and then only partitioned

How much are you writing to those drives? Have you tried any drives that will extend their pseudo-SLC cache across the entire space, and then only partitioned 25-30% of the nameplate capacity? That'll get you a terabyte for less than $300. Personally I've had two SSDs in active use and both have done a lot better than that. One was MLC and died after 13 years, and the other is TLC and still working after 10 years.