AHCI vs. IDE

[greekster]

Seagate's diagnostic tool, SeaTools For Windows, kept failing a Seagate 3TB SATA drive and a Hitachi 1TB SATA drive that are connected to the Marvell Controller ports on my ASUS P8P67 EVO Motherboard. SeaTools also classified both drives under the heading of "SCSI-FC-SAS" and the other 4 internal drives I have hooked up to non-Marvell ports as "PATA-SATA".

Also, SeaTools for DOS wouldn't sense the 2 Marvell drives or the other 4 internal drives either.

Then ASUS suggested changing the setting on the Marvell controller to "IDE" instead of "AHCI" and then the 2 Marvell drives were listed under "PATA-SATA" like the other four in SeaTools for Windows. And SeaTools for Windows passed both drives. SeaTools for DOS then sensed and passed both Marvell drives, but still did not sense the other 4.

Just wondering if I should leave the Marvell Controllers set to IDE or do you think the BIOS needed flashing? And then maybe I could change them back to AHCI? Is there much difference in speed between AHCI and IDE settings?

Any help would be greatly appreciated.

 

[scottiemedic]

It's ok to leave them IDE if you need to use SeaTools. IDE and AHCI are the same speeds, but AHCI allows hot swapping. If you don't need it, leave them IDE for simplicity.

The reason SeaTools can't find the drive on AHCI is cause the program doesn't have Marvell drivers built in.

You do NOT need to flash the BIOS to 'fix' it.

 

[Guest]

you also won't be using NCQ
http://en.wikipedia.org/wiki/Native_Command_Queuing

unless your accessing your disk quite about you are not missing anything, milliseconds at most. if you do change the mode, you will need to configure windows for the change before you change the bios settings:
http://bourlas.alloenablog.com/2011/01/09/how-to-enable-ahci-mode-for-windows-7-and-vista-without-format/