|How did you format the new HDD. Is it using NTFS or FAT32. You can check this by...|
Right-clicking My Computer
Select Disk Management on the left
Look at the File System Column for your Drive.
If it is FAT32 then this is your problem because FAT32 is very slow on large drives.
You can also download a speed tester for your drive...
That being said, I think your problem may not be the drive but may be other issues. It could be a hardware issue.
Did you visit Asrock's site to see if there was a BIOS update available for your BoBo?
If it is a Software Issue then we need to know...
How did your transfer your old Operating System from your old drive to the new one?
After doing a transfer did you do Windows Updates?