HDD on high load shortly after startup (WD30EZRX)

My OS is installed on a separate SSD and before I used windows and copied all my data on the drive it was nice and quiet. Now everytime I start up my PC it starts going loud after about 5 mins. I had the exact same problem with the Seagate Barracuda 3tb too which I took back.

Do you think it is just the sound of the 1tb platters or is my pc making hard work from the hdd even when its on idle? I had a Samsung 1GB F3 and that was super silent so Im used to my HDD beng almost inadible. 

You might want to try some of the suggestions on the following links. 

How to tell if the noise or sound the drive is making is normal

http://wdc.custhelp.com/app/answers/detail/a_id/568

How to test a drive for problems using Data Lifeguard Diagnostics for Windows

http://wdc.custhelp.com/app/answers/detail/a_id/940