My computer that is 3 year old has SATA 150 controllers. Since the standard now is SATA II or SATA 300/3GBps I was wondering whether it would be possible to boot the system from a drive connected to a SATA II adapter card sitting in PCI Express bus.
Go into your BIOS and see if the boot sequence allows you to designate that drive as a boot drive, and if yes, then you should be able to do it. You can boot from thumb drives when the BIOS allows you to direct the drive as a boot drive.
Is there a need for this new drive other than that you need a new boot drive because if that is the reason, the new SATA II are backward compatible with original SATA specs. The drive will just operate like an original SATA drive.
My internal SATA drives are hot swappable while the external (front and rear ports) are not hot swappable, according to mobo manuf. It should be easy to figure out if it will work or not.