Hey, I bought my macbook in late july and when I checked the drive speeds back then, both write and read were at about 1.1-1.2 GB/s. If I check them now I get write speeds of about 350-600 MB/s and normal read speeds. I went to the Apple Store today to deal with the coating issue and he told me it's normal for SSD's to degrade, but is half the speed really normal? Currently I have about 50GB free of a 256GB SSD (60 of those are configured for Bootcamp, which has like 10 free atm). So i don't think it's an issue with free space Their diagnostic tool didn't work so when I send it in, again for the coating, they'll check for the hard drive as well.