Z77 UD5H - windows 7 64 bit install only recognizes 746 GB of 3 TB

[Grogzelsteig]

I am trying to install win 7 64 on a 3 TB drive.  The drive reads as 746GB at the win7 installation screen.  I hooked up the drive to another computer and formatted the drive as GPT.  Also used seagate software to do the same.  The drive reads full capacity when hooked up to an already installed OS, but as soon as I try to install Windows on it, it shows up as 746 GB.

I have core i5 3570k and gigabyte z77 ud5h.  I have it set to RAID with seagate 7200.14 3 TB drive and a 120gb corsair force gt attached so I can set up intel smart response caching.

What am I missing?

[zerowing]

You need to use EFI install from Windows7 installation DVD. It must be installed in EFI mode for EFI boot. And EFI boot must be set in BIOS.

[Grogzelsteig]

I have the Boot drive set to the DVD and make sure to select the DVD drive with UEFI in front.  It still shows up as 746GB.  I am trying to install with it set to RAID so I can set up caching.  Just for kicks I set it to ACHI and it did show the full 3 TBs in Windows setup.  So it only the RAID setting that is causing problems.