Enabling the SATA AHCI setting

[memory]

What does the SATA AHCI setting do? If I enable this setting, would I have to reinstall Windows?

One reason I would like to enable this setting is because my transfer speeds between two hard drives have been pretty slow and I wondered if this setting would help the speeds out.

 

[carnageX]

It will enable certain SATA features (e.g. hotswapping).

Yes you would have to reinstall Windows; either that or you would have to do some system file modifying that is a PITA.

 

[memory]

Would it make a difference in transfer speeds?

 

[carnageX]

Benefits of AHCI ?

Last post on that page:

"1.7 Theory of Operation
AHCI takes the basics of the scatter/gather list concept of Bus Master
IDE, and expand it to reduce CPU/software overhead and provide support
for Serial ATA features such as hot plug, power management, and
accessing of several devices without performing master/slave
emulation."

 

[Apokalipse]

To enable AHCI, first you just need to enable the AHCI driver in Windows by modifying a registry entry.
Then you can enable it in BIOS and not have to reinstall Windows.

In:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Msahci\
change the 'start' entry to have a value of 0

 

[Jayce]

Is modifying settings to the OS exclusive to Windows itself in regard to AHCI and legacy mode? I'm just curious if you already have the driver pre loaded what harm it would be in switching it out like that. I did that on my linux box probably 6 times before I even knew what AHCI was and I had no issues. Never tried it with Windows, though...

 

[Apokalipse]

Is modifying settings to the OS exclusive to Windows itself in regard to AHCI and legacy mode?

I don't know every OS, so I can't say.

I do know that if you have AHCI disabled, and you install Windows, it will detect that the drives are not running in AHCI and thus not enable the AHCI driver.
So you just have to enable it yourself if you want to use AHCI.

 

[memory]

I have 2 hard drives, one is for storage. Would enabling the SATA AHCI setting cause me to lose all the files on the storage drive?

 

[InsaneJester17]

No it shouldn't. I've switched my drive back and forth to AHCI a few times. No files lost just by doing that.