I am not going to walk you through each step because thats what reading the forums is all about but i will outline the best practices for this board so you can look up how to do them if you don't already know. I recently set up a system with this board and everything is working perfectly including thunderbolt (though no hot-plug of course). Maybe i will do a full guide at some point but i don't have time right now.
0. Set up your BIOS correctly. The main things to consider are:
0a. AHCI for all SATA controllers
0b. XHCI and EHCI handoff enabled
0c. Thunderbolt security set to legacy mode and wake from thunderbolt disabled
0d. You will probably want to enable XMP profile for your RAM assuming you have decent modules
0e. Set your graphics the way you need them. I think best practice is set IGFX to enabled, 64MB and MAX DVMT and initial display to IGFX.
(For this to work properly you will need at least one monitor on the motherboard ports so you can see the pre-boot environment and for OS X to recognize the iGPU properly. You can then have one or more monitors on a discrete GPU as well. This has the advantage of quickync working (airplay video) and preserving some VRAM on your discreet graphics. I don't know anyone using a workstation without at least 2 monitors these days, but if you only have one, get another cheap one to run off the iGPU or disable the iGPU and set initial display to the PCIe slot you have your discrete GPU in. But i won't be covering how to run in that configuration.)
1. Install via unibeast or your preferred method
1a. boot into your new install and go through initial setup
2. Install Maciasl and apply the PJALM patch for this board. the Repo is back online for the time being.
2a. Depending on your hardware and setup you may also want to apply either or both the Toleda HD4600 DSDT patch (v3, ID1) and PJALM generic Discrete Graphics. I suggest applying both.
This will give you HDMI audio support and remove the need for an IGPenabler in boot plist.
2b compile the DSDT in maciasl and place it in /Extra folder
3. Run multibeast
3a. Realtek ALC/ with DSDT/ ALC898
3b. Select 3rd Party SATA !OR! 3rd Party eSATA depending on if you have any of the Marvell ports routed to eSATA ports
3c. Optional, enable Trim Enabler. I am paranoid about this and usually don't bother
3d. FakeSMC is mandatory. Fakesmc plugins are suggested. HWmonitor is optional.
3e. Intel hnak e1000e
3f. DO NOT install any of the other drivers or patches, many will screw things up.
3g. Chimera 2.2.1
3h. Basic boot options + Use KernelCache ONLY
3i. imac 14,2 system definition
3j. cham default 2.2 theme
3k. Build to your system drive
3l. again DO NOT choose ANY other options unless you know what your doing and have a good reason to.
4. Install and open Chameleon Wizard
4a. go to the SMBIOS tab and click edit
4b. select a premade imac 14,2. Then press random for week and unique. press random week again until you get a number over 40. press save.
4c. go to the modules tab and check FileNVRAM.dylib. press update for your system drive.
5. open disk utility and repair disk permissions for you system drive
6. reboot and test everything. enjoy your hack and start installing software.
7. At this point you may want to overclock which involves downloading pikeralphas ssdtPRGen script and running it with the frequency target you have in mind. Then you have to add DroppSSDT=yes to your boot plist (you can use chameleon wizard). Then you can go into the BIOS and set the max turbo states for the first core to that target frequency, and the other 3 cores to one step below that.
8. Install windows to enable thunderbolt functionality
8a. Unplug your OS X system drive temporarily, and plug a fresh drive into SATA port0.
8b. Install windows as per your preferred method, windows 7 x64 or windows 8(.1) x64 will work.
8c. Install all the drivers from gigabyte's site for this board, especially the Intel INF driver and Thunderbolt driver.
8d. Reboot and make sure the drivers installed correctly.
8f. You can now either keep the windows disk if you plan to use windows for games, or repurpose the drive. Put the OS X system drive back on SATA port 0 and if you are keeping the windows drive, put it on one of the other ports. Make sure the OS X system drive is the first boot option in the BIOS and you will be able to select which OS to boot from Chimera.
Thats all you need to do in an outline. And that's all i can contribute for now.
g\