Why does my 3TB hard disk fail to boot when I switch the controller from AHCI to RAID?

Something I have noticed: using diskpart while in the command prompt in disk recovery tools it says that the drive is 700 GBish while the controller is in RAID, but correctly determines 2.7 TB while it is in AHCI.


Disk0: 128 SSD Drive (clean, no partitions)
Disk1: 3 TB Hard Disk (GPT Partitioned)
    Partition 1: EFI 102 Mbs
    Partition 2: MSR 32 Mbs
    Partition 3: Primary (whatever remains)
Motherboard: Gigabyte Z77-DH3 (supports UEFI)

Idea: I want to use Intel Rapid Store to make the SSD a cache.

Any help is greatly appreciated.

  • Did you wipe the disk and reinstall the operating system after switching the controller mode? Jul 18 '12 at 5:16
  • I tried that, problem is that anytime the controller mode is RAID, the Sata drive appears to only have 700GB instead of 2.7 TB
    – chacham15
    Jul 18 '12 at 6:35
  • Is that when booted to the Windows 7 setup DVD? Do you have any Intel documentation on how you're supposed to configure the RAID mode? For example, perhaps you have to install Windows on the 700GB virtual disk first so you can install some sort of RAID configuration software? Jul 18 '12 at 19:54

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.