I mentioned this in passing in my thread bitching about D2D. There is now more to the story, so I'm restating the issue here.
OK, I have 4 SATA HD's and a SATA Blueray/DVD drive in my main machine. The MB has 6 SATA ports controlled by the Intel ICH10 Southbridge chip. And 2 SATA ports controlled by separate Gigabyte SATA2 chip. Now the Gigabyte has always been disabled and everything was on the Intel controller. I had it set to run in AHCI mode.
Last week my main HD and another one stopped being recognized by the BIOS when in AHCI mode. The Windows install became trashed because of it. I tried every drive in every Intel port and the three that were working were recognized in all of them and the two that weren't recognized didn't work in any of them.
So I switch to IDE mode and all the drives were recognized. I then reinstalled Windows.
On a whim I thought I'd see if for some strange reason they would be recognized in AHCI mode again. So I enable the AHCI driver in Windows and proceeded to reboot. Switch to AHCI in the BIOS and low and behold, my main drive was recognized. But not the other one.
Now another on a whim moment. I enabled the Gigabyte SATA chip, set it for AHCI, and connected the still offending drive to one of those SATA ports. Guess what? It was recognized!
So now all the five drives are back to AHCI mode. But one of them is on a separate controller. To recap, at this point I have three HD's and an optical drive that are recognized on eight different SATA ports when in AHCI mode. And one HD that is only recognized in AHCI mode on the two SATA ports on the seperate controller.
So if anyone was able to follow this long dissertation, I'm wondering if anyone has a clue what happened.
edit: Oh, and the reason I thought to check to see if for some reason the offending drives would miraculously be recognized again in AHCI mode is that there was a noticable slowdown in boot times and program launch times which were unacceptable to me.