1. Crystal Disk Info doesn't even show the drive. 2. Hard Disk Sentinel shows the drive, has Health as unknown. Performance as Excellent. It has a Temperature tab which shows temperature for the drive! 35C. Max and average. Of course I don't know if it is real or not. 3. I found online someone else (two actually) having the same issue with similar Adata nvme drives. Now this guy doesn't use Windows 8.1 but I assume it might be the same problem. and I quote: If this is indeed the issue, not some bug, this is obviously the first and last time I buy anything Adata related. Not sure if I am going to return the drive or not.