AHCI on/off performance

[richk]

I haqve an application that will not work with SATA compatibility set to "AHCI". What sort of performance hit should I expect if I turn it off and reinstall windows.

[erik]

you can test this for yourself.   download and run hdtune, taking note of the results.   reboot into the BIOS and set SATA to compatibility mode, then go back into windows and re-run hdtune.   the results probably won't be that much different but i must admit that i haven't tested this myself.

btw, you don't have to reinstall windows to run in compatibility mode.