Bandwidth sharing on IDE

Has anyone had a problem with two HDs on one ide, where when accessing one of them the whole computer bogs down like it's out of RAM? It's weird... acessing my MASTER drive makes my entire computer get slow... even when I switch the drive arrangments, the problem follows the drive... but it used to work, and the old drive I had did the same thing after about 7 months. When I got the new one, it worked for about a week then started doing the same thing the old one did... could it be bandwidth sharing? Has anyone ever seen this b4?

I would run diagnostic tests on both your HDD's, most HDD manufactures have software you can download to test their HDD's out...