Hey All, sorry if this is the wrong forum to ask this, but I couldn't tell where this belongs. this is bit of a tricky, but been doing a ton of research on this and from xlr8 your mac website, mac rumors, etc. and found this: http://www.reddit.com/r/apple/comments/1rsp3q/install_mavericks_on_older_mac_pro_11_21_20062007/ Essentially, I'm trying to get my 1.1 from 32bit to 64 bit and then install mavericks/yosemite. I've followed everything on a video and on the Sixty-Four On Thirty-Two websites (SFOTT) but I've come on a weird problem. I've upgraded my video card to the ATI Radeon 5770 which was flashed for a Mac but doesn't display boot screen, I hold down Option, Command+R or C or anything to choose the USB drive to install mavericks but, I get nothing. I took out the 5770 and put in the original gpu. Everything boots up. I hold down option and I don't see the usb drive selected, just my macintosh hd drive on the computer. I then tried each usb slot to see if there was something funky going on, but some of the time I would get the boot screen, sometimes not. Anybody have any ideas about this or a work around? I'm giving up for the night but I'm thinking about trying to use target disk mode and installing from there or just use the the HDD/SSD and install it onto there, then pop it back into my 1.1.