I'm beyond frustrated. none of this makes any sense. I have 2 of these, and one of my drives was slow from almost the beginning. at like 20% full, it was at 1000MB/s. I switched it to secondary/non OS drive, so I could delete it and return it, and I was getting the full speed again. I had done an advance rma, so I returned it anyway. the new one was working fine, but the speed tanked to 1000MB/s again. it's 25% full. my other drive has never had any issues whatsoever.