I’ve recently bought the WD15EARS-00S8B1 drive. I was having similar issues with it as many people on this forum seem to have with the Green series drives, aka disk becoming very unresponsive and reporting 100% load to Windows even when there’s hardly anything going on. Watching videos and even just listening to music files would halt and make the player application unresponsive. My Intel X-25M SSD and Samsung F1 7200RPM drives on the other hand have functioned flawlessly.
However, when I put my F1 disks to Windows Dynamic Disk Striping mode, AKA Software Raid-0, they started behaving exactly the same way. This lead me to test different things and noticed that dropping the drives from AHCI to IDE mode solved the issue for me completely. Both the WD Green and the Samsung Raid-0 are working fine now.
I do not know if the problem I was experiencing was the same as so many people here are, but I thought I’d drop by with my experience just in case. My motherboard is the Asus M4A78-E. I was using the default Windows 7 AHCI drivers.