Not trying to jump on you or your post, sorry if it came across that way. I appreciate any help and advice you can provide. I don't think that an update is causing my issue. After the original drive passed WD diagnostics, I reformatted it and restored my MFS Live backup to it. So both the WD10EURX (AF) and the original WD10EVVS (non-AF) have the same software. There is a huge difference between the two, with the non-AF drive providing much better performance.