On Fri, Jan 21, 2011 at 12:53 PM, <meino.cra...@gmx.de> wrote: <SNIP> > Hi Dale, > > *IDEA* > > Mark said, that the kernel alone is defining, whether to talk AHCI or > IDE to the harddisk and there is not a single result here from my > experiments, that makes me believe, that Mark is wrong with that... >
Mark also said 'Don't trust Mark' so be careful about anything Mark says here! ;-)) > Why not to switch back to IDE in the BIOS, which again makes it > possible to boot from USB/DVD since it is used far before the > kernel image takes over. > If Mike's assessment is correct then the reason not to do that is that once the kernel boots it wouldn't know that the hardware is AHCI capable and you almost certainly would get lower performance. > When the kernel boots, the chips are "brainwashed" and after that they are > "thinking AHCI" instead of IDE.... > I think it's more what Mike suggested. The chips have a control bit in them that changes the way they work. If the bit is set to IDE then then chips never tell the kernel that they can do SATA so the kernel never tries. I booted into BIOS here. I have an option called "SATA Configuration" which is set to Enhanced. It offers Disabled and Compatible also. BIOS then gives me another choice "Configure SATA as" which I have set to IDE. It offers RAID and AHCI also. This allows the system to boot CDs and still allows the kernel to run SATA at full speed. - Mark
