Any Advantage to Using AHCI iso IDE in non-RAID Multi-Boot?

Any Advantage to Using AHCI instead of IDE in non-RAID Multi-Boot?

I don't use RAID because of previous experience with crashing and losing everything several times so switched to IDE ages ago and use all my HDD's in the 'old-fashioned' way.

I've been reading online that many have benefited from added system speed by enabling AHCI and apparently it can be done without formatting by doing the following before adjusting the settings in the Mobo BIOS.

Goto Key:-
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\msahci
Set start to 0, (default is 3)
Do the same with the pciide start key
reboot
set ahci to enabled in bios... or disabled
and ahci or standard mode is then installed by vista.

I'm surprised to find out that the registry keys are already set to '0' in my main Vista as are the rest of the quad boot.

To anyone in the know is it worth the effort or leave things as they are? The only thing that prompted me to look into this was in Win 7 my WEI was held back at 5.9 simply by hard drive Disk Data Transfer Rate, the rest being much higher. Obviously not really that important but anything that improves system performance is good.

Look at my system specs for more info. All drives are SATA as are the optical drives. Alienware in its infinite wisdom for some reason connected the built-in multi-card reader to the floppy connector on the M/B. That's the only oddity.

Would it effect XP VM's installed within Vista/Win 7 ?

OK being the impatient type I went ahead and did it and everything is fine after drivers were installed and reboot was required...in each of the 4 boot OS's. It appears to be much faster although my WEI hasn't improved. (I know 5.9 is the max in Vista but was hoping for 7.6 in Win 7 and didn't achieve it....still 5.9 for data transfer).

Anyway everything is fine except now I get the following right before the OS comes up....

"CD_ROM Boot Priority (xxsec) - no medium"

The bit in brackets isn't always there.

My boot priority in the BIOS is 1: my 1st DVD Burner 2: my 1st HDD and 3: Disabled

I've researched online and apart from removing the optical drive from the boot sequence which I've never needed to do in the past, I can't see any settings that I can alter to get rid of that.

Ideas anyone?

...this time I'll have to patient....;-)

Edit: made optical drive 2nd boot device and now I don't get it. It still shouldn't happen, however as I shouldn't have had to do that.

Not sure if this has any bearing...in the BIOS I now have two drive timeout settings...one for IDE and one for AHCI, does that have any bearing? (Both default 35sec)