840 has TLC, 840 Pro MLC TLC cells should sustain 1-1.5K Program-Erase cycles MLC 3-5K P/E cycles eMLC 10-30K P/E cycles SLC >100K 256GB eMLC SSD with 10K

840 has TLC, 840 Pro MLC TLC cells should sustain 1-1.5K Program-Erase cycles MLC 3-5K P/E cycles eMLC 10-30K P/E cycles SLC >100K 256GB eMLC SSD with 10K PE should be able to sustain 2.56PBW, which is pretty much what the 840 Pro 256GB with MLC was able to sustain in the test. Also enterprise ssds usually come with huge overprovisioning, a raw 1TB drive usually comes with 800G usable space. I had few 720G fusion iodrives with 1.1PBW and 0 reallocated sectors, and these were rated 10PBW.