On 03.12.18 11:35, Felix Held wrote:
No idea why combined mode is the default, it's only useful for OSes from the '90s. It's not about the type of drives (SATA vs PATA) connected but how the SATA controller identifies itself to the OS.>
I agree that the combined mode isn't the best default, but I can't say that it's totally useless. In combined mode you have the first 4(?) SATA ports connected to an AHCI controller and the last 2(?) to a legacy IDE/ATA controller. I had some SATA->PATA bridge to connect a PATA device to a mainboard and the adapter I had only worked on SATA ports that were connected to a legacy IDE/ATA controller, but not on SATA ports connected to an AHCI controller. I didn't further debug that issue though, so I can't say why it didn't work on an AHCI controller.
Interesting use case. I missed that the combined mode is also the only mode where you have SATA ports on AHCI and the legacy interface.
I also don't know if an IDE drive should work with AHCI. My guess would be yes, but OS drivers probably don't expect it.
Nico