Windows is not a quiet OS. It will on a schedule check a folder, write a log entry or do something. So the heads in the other drive might "seek" and make a little noise. Some owners are troubled by noises and over the years I never found a good way to placate them all. SSD helps but then the owner was disturbed by fans.
At least that iPad is nearly silent but then again I had this one client that could hear something. They showed me where it was by putting the pad to their ear. Not exactly how I would use an iPad.
My Vista 32-bit computer has two hard drives. I replaced the main drive with a Samsung SSD. However, I can still hear some noises from the 2nd hard drive.
Once every 5 seconds or so, I would hear that the 2nd hard drive is doing something. Is this normal? How do I find out what it is doing?