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One reason you might want to use a Mac-specific graphics card versus a flashed Windows version with Yosemite!

I'm going to post this in its own topic, but posting here because this is important and might bite someone with a Windows version graphics card flashed for Mac.

If you have a Snow Leopard partition and you use Startup Disk in the System Prefs in Yosemite to set your Mac to boot from Snow Leopard, it will work fine. However, if you want to then reboot in Yosemite, Startup Disk in Snow Leopard DOES NOT SEE THE YOSEMITE PARTITION. You can not choose it and thus boot from it on restart. You must restart and then hold down the option key on reboot and then select the Yosemite partition to boot from that way. And from what I understand, only Mac-specific graphics cards will show you that screen. If you have a Windows version flashed for Mac, you're flying blind and not sure how you'd get around this and be able to choose your Yosemite boot disk.

Just a caution. This what I found. My Yosemite disk is a SSD with Trim Enabler doing its thing, but I don't think that's the reason it can't be seen under Snow Leopard.

Interesting. Short of setting up a spare drive specifically to test that, I have no way to do so.

Is it just a problem with 10.10.0 and SL, or other earlier Mac OS X versions too? I had problems getting ML to start up once running in 10.10. Eventually it worked, but took a few restarts and only works from an Option restart.

bayswater wrote:Is it just a problem with 10.10.0 and SL, or other earlier Mac OS X versions too? I had problems getting ML to start up once running in 10.10. Eventually it worked, but took a few restarts and only works from an Option restart.

I had no problem with Mavericks and Yosemite.

I do have that issue on the G4 where I have OS 9, 10.4 and 10.5

bayswater wrote:Is it just a problem with 10.10.0 and SL, or other earlier Mac OS X versions too? I had problems getting ML to start up once running in 10.10. Eventually it worked, but took a few restarts and only works from an Option restart.

I only can vouch for SL. If I boot up my MacPro 4,1 in SL and then open System Prefs and choose Startup Disk, my disk with Yosemite installed is not one of the choices. I have no choice but to just choose "Restart..." from the Apple menu, and then hold down the Option key during the reboot so I can then select my Yosemite drive.

Don't know if this applies, but AppleSupport told me that the difference in disk structure between Leopards and Lions (or later) was great enough that the two cats could not see one another's discs. Which is why I couldn't read my Time Machine backups after going to Lion. Which is why I have never since upgraded anything without a solid, bootable clone of the startup disc. That was a mistake so enormous s it will not be repeated.