It has been a topic of discussion by many, MLC, TLC, QLC but the holy grail in relation to endurance still is SLC written NAND, that however is expensive. Well, Trancend is thinking outside the box and is releasing an M.2 SSD that is written 100% SLC.

The number of data rewrites is 100,000 times, which is about 32 times higher than your average "BiCS4" product. In addition, quality has been improved by producing high-quality FGT DRAM cache manufactured by major manufacturers and manufacturing at our own factory in Taiwan. Ideal for applications with high writing frequency, such as servers, medical equipment, monitoring systems, and terminals. The capacity lineup is available in three models: 64GB, 128GB and 256GB. Transfer speed is 560MB / sec for sequential reading, 420MB / sec for writing, 56,000IOPS for random reading, and 75,000IOPS for writing.

So yeah, it is not fast by any M.2 standards, and basically they are using a single bit per cell on BiCS4 Toshiba 3D TLC NAND. that thus operates in SLC mode. But here's the cherry on top of the cake: ... the write endurance is 3,600TB for 64GB, 7,200TB for 128GB, and 14,400TB for 256GB. Prices have not been announced.