I have two Hard Drive's > 500g and a 750G both GUID on this HP7700
500g has Maverick and Windows 8.1 installed> 500g main was erased Fat32 then Partitioned , two 250g partitions. one for windows and one for Mac.
I tried to install Yosemite on 750g with 3 partitions , no luck , Main has to be formatted GUID, mac j extend, then partitioned.
So I created the 8g chameleon 2377 yose installer. used chameleon 2377 yose boot loader At boot it would only see the USB. After many hours, I had a brain fart
I created a 320g usb with 2 Partitions 30g and 300g. made 30 G the installer and then I installed yose on 300g USB. I could have used the 8g !
installed Yosemite 2377 bootloader on 300g usb , looked good but stuck at waiting for device.
I download the yosemite kernel and extra file. then booted to Maverick and moved the kernel and extra file to Usb Yose. Booted stuck at waiting for dsmos . reboot flag -f -v -x Graphics Enabler=no Yea booted up. running very slow.
Later !, I used Chameleonlist on Mav to set the yose drive sbois to Mac Pro 3.1 and set up boot and play list
I booted to Maverick created a Yosemite 300g IMG and restored to 750g first Partition.
I Followed all the basic rules except erase 750 main Mac journaled extended.
I use a 8g usb drive with yose 2377 bootloader at boot , then chose what I want to boot.
Audio =no > wireless board and mouse slow. >Bluetooth maybe.