My 4T MyBook studio II (RAID 1) is currently running very slow. On a 2014 iMac core i7 running Mac OS 10.10 (Yosemite), it takes 8 min to copy a 100 MB folder (containing 30 files) using the FW 800 port or 3 min using the USB port. Copying the same folder on a G-Drive 750GB takes less than 5 sec using either the FW800 or the USB port.
In order to find a solution, I have reformatted the drive with Apple Disk Utility, reinstall WD Drive Manager Installer (3.1.0.14) and WD + Turbo installer (1.3.7) and I have tried RAID 0 and 1. The drive is still very slow. I have tried to install the last WDFirmwareUpdater (3.2.4.4) , but the installation fail (several times).
Might the problem be due to Yosemite? I don’t know whem the problem has started.
