Now that you have 4 drives inside the case, I urge you to find some way to monitor the case or CPU temperature. If the case is poorly cooled, you may need to add extra cooling to preserve the chips in the new drives. I lost a couple of drives before I identified and solved the problem. In my case the answer was Kingwin mobile racks made of aluminium with extra cooling fans. It brought the temperature down by more than 10º F.