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AHCI or IDE mode

idata
Esteemed Contributor III

Whenever i choose AHCI mode in bios, sometimes there is a long delay (1 minute) at boot time. Workaround is to choose IDE instead, eventhough i experience better performance using AHCI. Is this a compatibility issue with my motherboard (rampage 2 extreme x58) or with some drives in general? I do in fact have an optical drive on a pata controller (jmicron jb363) which if not mistaken can lead to problems using AHCI, so i guess i should either not use it or replace it with a sata version.

Any suggestions?

21 REPLIES 21

idata
Esteemed Contributor III

Most motherboards do exactly what you are describing. Some take longer than others. I have 5 drives in my system and if I switch to AHCI it takes about 25 seconds for it to see everything. After that it remembers all the drive info and boots right up. The reason is that when you go to AHCI mode the bios has to look at each drive and see if it is AHCI compatible and get the drive info, SMART attributes, whether or not it supports NCQ and a few other little goodies it has to get. It queries each drive to get that info and that is what takes the extra time after you switch to AHCI. Once the bios has all that info it shouldn't have to figure it out again unless you go back to IDE mode and then switch back to AHCI again. If it does it every time you boot you probably have a problem or a setting out of whack. The jmicron PATA controller shouldn't have an AHCI switch as it is not an SATA drive or controller.

idata
Esteemed Contributor III

Problem is that sometimes AHCI mode does not take the extra time to boot up. In general it will take around 18 seconds, but once in a while it'll get stuck at the windows logo and takes up to 77 seconds. I'm leaning towards thinking its a compatibility issue with the IDE cdrom.

idata
Esteemed Contributor III

Taking longer to boot in AHCI mode is normal as someone explained to you above. Depending on your BIOS, the time can vary, and it is possible a newer BIOS update would help; for example, I updated my BIOS and it had a newer AHCI ROM that speeds things up a bit. Check the BIOS updates for your motherboard and maybe there is a newer version that would help.

idata
Esteemed Contributor III

What Guz is describing appears to be the storage controller driver taking a long time to talk to one of the connected drives. It's during this Windows logo time that the drives are enumerated. Since IDE vs AHCI can cause a different driver to service the storage controller, this change could affect behavior. Disconnect drives to find out which one is causing the problem. And when I say disconnect, I mean both the power and SATA cable. I've seen trouble with just a SATA cable connected.