Posts tagged ‘AHCI’

Hard Drives in Windows 7 Randomly Appear and Disappear

Long-time readers will understand immediately that this is not a post for regular readers but is meant to be found on Google by people with similar problems.

I installed Windows 7 home premium 64-bit on a new Asus motherboard with an Intel Z97 chipset.  I have a couple of hard drives and a couple of RAID's connected by eSATA.  Once the installation was complete, I noticed one of the hard drives was missing from the drive listing.  Not only was it not recognized by Windows, it was not recognized by the Windows disk management utility or even by the BIOS.  So I rebooted, and found that this drive now appeared but another disappeared.  This kept happening over and over.  Some reboots I had them all, and some I did not.

I did all the usual stuff.  I swapped cables, swapped drives, etc.  I even RMA'd the motherboard when I got desperate, thinking there was an issue with the drive controller.  But it kept occurring on the new board.  I considered switching the drives from AHCI to IDE in the BIOS, as some people reported this fixed the problem for them, but I really wanted to avoid that**.  I updated the chipset drivers and all the other drivers (sound, graphics, etc) in case there was some IRQ conflict, as some people have reported that this fixed their problem.

I finally found a fix, and thought I would share it.

  • Check your power plan in Windows control panel.  Even if the computer is set never to sleep, your hard drives may be set to sleep (this is in fact the default in windows 7).  Go to the power plan advanced settings, look for hard drives, and set the time to sleep to 0 which causes them never to sleep.  I am not sure this is necessary but others report some success with this.   I may go back later to see if I can change it back -- I don't necessarily need my hard drives spinning all day.
  • It turns out that installing the Intel chipset driver is not enough.  I had thought that since the SATA controller is part of the chipset, the chipset driver would cover it.  However, once I installed the Intel chipset driver, when I checked the SATA / AHCI controller in device manager, it still showed the driver to still be a Microsoft driver.  Turns out this is the problem.  You need this to be an Intel driver
  • The drivers I wanted for the Z97 were right there on my motherboard support site and were called:
    • Intel AHCI/RAID Driver Path for Windows Win7 32bit & Win7 64bit & Win8 32bit & Win8 64bit & Win8.1 32bit & Win8.1 64bit.
    • Intel Rapid Storage Technology Driver software V13.1.0.1058 for Windows Win7 64bit & Win8 64bit & Win8.1 64bit---(WHQL).
  • I had originally thought these were some sort of utility (and a utility is included) but these are essentially the eSATA drivers I needed.  Once installed, checking device manager now showed an Intel rather than a Microsoft driver.

And that fixed it.  Ugh.  Hours and hours of frustration.  My apologies to Asus who got a returned board that was probably just fine.


** By the way, the reason switching to IDE probably fixed the problem is that it is a different driver.  But one gives up capabilities and a bit of performance going AHCI back to IDE.  Also, the switch is not entirely straightfoward and the switch back, if one ever wants to make it, is complicated.