What is SATA RAID/ACHI Mode

[SBMongoos]

I have the EP45-UD3R. I see the SATA RAID/ACHI Mode but not clear on what it does. It's currently disabled.

I'm using SATA drives but not sure I'm taking advantage of their speed. I understand there is an IDE and SATA/ACHI mode if I understand correctly.

[mv2devnull]

Re: What is SATA RAID/ACHI Mode

The SATA controlled has three personalities, and one has to choose one, in practice before installing OS. And stick with it.

First is traditional IDE mode (as in how the SATA controller talks to the SATA drives).

The second is AHCI mode that knows extra "phrases", possibly making the disk access more efficient. (But not always.)

The third is the RAID mode. Controller talks AHCI to the disks, but can present the drives to OS as (redundant) logical arrays.

[kantona]

Re: What is SATA RAID/ACHI Mode

Any way to 'calculate' whether AHCI will be better than IDE mode?

[SBMongoos]

Re: What is SATA RAID/ACHI Mode

Sounds like the way I have that function set in the BIOS, disabled, makes sense. I'm not using RAID and based on what I had read about AHCI it didn't sound like I was really going to benefit from it. I'm running WinXP Pro SP3.

[pbcopter]

Re: What is SATA RAID/ACHI Mode

I use ACHI to allow for hot swapping my SATA drives that I use in front accessable hard drive trays.

[SBMongoos]

Re: What is SATA RAID/ACHI Mode

I use ACHI to allow for hot swapping my SATA drives that I use in front accessable hard drive trays.

R u using Vista?

[Th3_uN1Qu3]

Re: What is SATA RAID/ACHI Mode

AHCI will allow hotswap in XP too. But you will have to reinstall to get it to work. And it adds an extra 10 seconds to the boot process due to the silly Intel SATA BIOS that doesn't give you the option to switch detection to manual, and scans all the ports every time you boot.

[NZMks]

Re: What is SATA RAID/ACHI Mode

I hot swap SATA HDD's in IDE mode (using eSATA) and it works fine, seems to only work on Gigabyte Sata ports though...

[Comers]

Re: What is SATA RAID/ACHI Mode

Any way to 'calculate' whether AHCI will be better than IDE mode?

It depends on how you normally use your pc. If you just browse and chat there is no benefit from ahci mode. But if you like to switch between many applications utilizing heavy background disk operations, such as video encoding, multiple torrent download, streaming etc..., you then would benefit more from NCQ (native command queueing) feature of ahci that basically will cut down your disk access time noticeably. That's of course if your hard disk support it, but nowadays all of them do.
Well, if these 10 sec boot delay drive you crazy, then consider working in pure ide mode and change your disks every 1-2 years.

[Comers]

Re: What is SATA RAID/ACHI Mode

AHCI will allow hotswap in XP too. But you will have to reinstall to get it to work. And it adds an extra 10 seconds to the boot process due to the silly Intel SATA BIOS that doesn't give you the option to switch detection to manual, and scans all the ports every time you boot.

AHCI allows hotswap natively on controller level, but usually there are no many applications that give you that option. HotSwap! can help you there.
No, certainly you don't have to reinstall XP to enable achi mode afterwards.
There are maaaany posts how to do it either in ahci or in raid mode. It takes 5 min + 2 reboots to do it.