Just installed the Samsung 850 Evo 1TB after cloning from a 512TB Samsung 840 Pro, which took about an hour. After cloning and creating a recovery partition, I have a 999GB boot partition of which I’m using 324GB. Performance on the 512GB was starting to slow down. I think partly from age, and mostly from space. Now I’m less than 50% full again and thus getting write speeds of 470MB/s and read speeds of 515MB/s. Not too shabby. Boot up time takes about 10 seconds again!