I just received my 5th WD20EARS and when i hooked it up it wasn't detecting it. It reads 1-4 but not 5 and 6 i have MOBO ASUS M4A785-M under the bios it shows port 1-4 AHCI and 5-6 AHCI i tested different cables and nothing seemed to work until i changed the 5-6 port to IDE and now it detects them. I loggd onto //tower:8080 to verify everything was detected and it does but now the 5th WD20EARS is shown as a IDE /dev/hdc should i go ahead and preclear it like this or would that affect the drives speed or functions? I a lso i installed a jumper on the HDD i really don't know what else to change to make it detect under AHCI any suggestions or help would be appreciated, or should i just let it read it as a IDE.

I know on other ASUS motherboards if you have the first group of SATA drives set to AHCI it will not detect the remaining SATA ports. If you have the first group set to IDE this is not an issue for the second group. A driver is required to detect the second group of drives if you want the setting to be AHCI. I looked at the manual for your motherboard and it does not say this but I know for a fact on other ASUS motherboards that this is the way the SATA ports are handled.

IDE may perform slower than AHCI. Check for a BIOS update for the MB.

I just received my 5th WD20EARS and when i hooked it up it wasn't detecting it. It reads 1-4 but not 5 and 6 i have MOBO ASUS M4A785-M under the bios it shows port 1-4 AHCI and 5-6 AHCI i tested different cables and nothing seemed to work until i changed the 5-6 port to IDE and now it detects them. I loggd onto //tower:8080 to verify everything was detected and it does but now the 5th WD20EARS is shown as a IDE /dev/hdc should i go ahead and preclear it like this or would that affect the drives speed or functions? I a lso i installed a jumper on the HDD i really don't know what else to change to make it detect under AHCI any suggestions or help would be appreciated, or should i just let it read it as a IDE.

 

I had exact same issue on one of my AMD mobo's. Look for a setting called "SATA IDE Combined Mode". For mine, was actually in the Southbridge configuration. Soon as I disabled that. all drives detected on AHCI as "sata".

 

Shawn