Thanks for joining the community.
I am sorry to hear that have had problems setting up SATA drive.
This problem does not seem to be an issue with the Intel chipset nor rapid storage.
I believe this could a problem with hard drive, computer BIOS or the SATA port on the computer. When you initialize 750GB hard drive it will not take that amount of time.
Please try getting hard drive diagnostic tool from your hard drive manufacturer and latest computer BIOS.
Thanks for your reply.
Unfortunately I've had to remove the drive as 24 hours later it still had not finished messing with it (apparently), and it was still slowing my system down. I will try it as an external drive by getting a suitable caddy and using a USB 3 port, and see what happens.
In the meantime I have downloaded all the chipset driver updates and applied a few, but had not got to the AHCI or BIOS yet - I will do that this weekend.