[Nooblit]

i have 2 500 gb sata harddrives that a picked up when i built this computer, all i did was plug them in and start using them, but I believe i heard a while back that sata hard drives put in legacy hdd mode or ide mode go a lot slower than they should. now i'm pretty sure my hard drives are in this mode. if you can't already tell i have no idea about this at all, i was hoping someone could shed light on this stuff. thanks in advance and +rep to all who help.

 

[mcastaneda68]

You are right. In order to take advantage of the full advatages of SATA drives, such as NCQ, you need to make sure that the drives are set to run in AHCI mode in your BIOS screen.

Unfortunately, if your drives were setup in IDE mode, I don't think you can just change the mode. You will need o re-format.

 

[Nooblit]

Quote:

Originally Posted by mcastaneda68 You are right. In order to take advantage of the full advatages of SATA drives, such as NCQ, you need to make sure that the drives are set to run in AHCI mode in your BIOS screen. Unfortunately, if your drives were setup in IDE mode, I don't think you can just change the mode. You will need o re-format.

well it's not that big a deal, aside from having to reinstall vista... and installing OS's is a nuisance. drivers, programs, yada yada... but now that i know, next time i do, i think i might set it up in AHCI mode.

one more question though... if you do set them up in AHCI mode, can you throw them back into IDE mode if you needed to without reformatting?

 

[blatsha92]

another question regarding this...if i have 1 SATA and 1 IDE drive, can i use AHCI mode? or will my IDE drive no longer work?

 

[FREELINE57]

Nooblit, also if you install in one mode and change modes it will not boot to my knowledge, the reason i say this is because i believe i read this somewhere a while back.
So if u formatt and install say IDE mode I'd leave it at that.

 

[Melcar]

There is no performance difference between "native IDE" and AHCI. Only difference are the extra features in AHCI mode, so if you don't use them just leave your controller in IDE mode (which is the default on most boards).

 

[mcastaneda68]

Quote:

Originally Posted by Melcar There is no performance difference between "native IDE" and AHCI. Only difference are the extra features in AHCI mode, so if you don't use them just leave your controller in IDE mode (which is the default on most boards).

I may be wrong, but setting the drives as IDE instead of as AHCI, will reduce performance because of NCQ (Native Command Queueing), which allows the drive to "smartly" decide wich packet read from the drive (when there are 2 or more concurrent reads)

 

[Melcar]

That matters most on server like environments. For the more common single HDD desktop user it makes little difference. Again, if you need the extra features AHCI allows then turning it on is obviously the best choice.
Most boards default to what some BIOS label as "legacy IDE", which is the older IDE interface. This is just to ensure proper compatibility with operating systems (WinXP for example won't boot in AHCI unless you install drivers separately). Modern Linux kernels and Vista have built in AHCI support now, so turning it on doesn't matter as far as compatibility goes. The safe option is to leave the controller on "legacy" mode, but if you're using a new operating system (or have the proper drivers for old operating systems) then you may as well turn it on. Still, it's not like AHCI will magically double your read/write speeds in a single drive configuration.

 

[Nooblit]

well this thread has put it into perspective a bit. thanks a bunch guys. +rep to everyone.