Any other benefit to flashing the GPU

[pastrychef]

The GTX 680 also has enough room since it is possible to flash to a Mac Edition card pretty easy. I don't think that newer cards have less space than the GTX 680.

Yes, I'm well aware of the GTX 680s. I flashed my own. I was just adding the 8800 GT and 8800 GTS to the list since every seemed to forget about them in saying the GTX 680s were an exception.

(Thanks again to Dr. Stealth for finding and sharing the GTX 680 4GB firmware.)

 

[pastrychef]

Not enough room on other cards for the EFI. EPROM needs swapped for a larger one. This has been said before but you seem to be missing it.

You should really do some reading on this forum about this topic. It's all there for you if you just look.

Where was this confirmed?

 

[Fl0r!an]

Thank you for your reply, as this is the most useful reply I have received so far. So it is basically hacking existing firmware. This is interesting. Do you have any documentation, links, and recommendations for tools to get started?

There is (sadly) no "Getting Started" or any other kind of "complete" documentation on what is know today, most information is at netkas forum scattered over many threads. I'd recommend you my thread about improving Radeon ROMs since it contains quite a lot of basic stuff.

 

[Synchro3]

I am sorry, I was not trying to upset you. I didn't understand what it was all about, and probably I still don't, since both 6 pin and 8 pin cables exist for the Mac Pro. There are also 6 pin to 8 pin adapters.

Yes, there are 6 to 8 pin adapters, but with the MVC EFI you don't need them, which is the better solution I think, just plug in the 2 @ 6 pin cables (the 6-pin cables only fit into the 8-pin port one way). Try this with a vanilla GTX 770 or 780 PC card and the MP won't even boot up.

 

[benjaprud]

I think that's because MVC shorts the pins on the PCB to allow you to use a 6 pin cable and has nothing to do with EFI (but is still part of the MVC mod). With a vanilla card you will need a 6 to 8 pin adapter which achieves the same thing, or you can also short the pins yourself.

 

[Thessman]

Is it fine to run leave this in the machine along-side a gtx 970? I'd have the display plugged into the 970 and just leave the 120 for when I need a bootscreen.

Will this work in Windows too?

There was a thread about this recently but it was inconclusive.

You can leave it in, or you can take it out, when you press tha alt key during boot, the disks are always in the same order, so if you remember which is which you can choose the one you want with the arrow keys, and then press Enter.

Your other option if you have to see the boot screen, is to replug it in when you need it.

 

[star-affinity]

• Ability to install Windows 8.1 in EFI mode instead of BIOS emulation mode, with related benefits such as fast boot, faster drive access (AHCI mode), and having native GPT partitions instead of that hybrid stuff.

This I learnt the hard way the other day. I had a working Windows 10 installation on my MacPro5,1 (Mid 2010) and non-flashed GTX 970 (so ”hybrid partition stuff”) and then for testing purposes I put in the AMD GPU that came with the computer in and started up in Windows 10 using that. Worked fine, but after putting back the non-flashed NVIDIA GPU I couldn't start into Windows 10 anymore – I just got reverted back into MacOS. And trying to bless the Windows 10 drive via the Terminal (I had SIP disabled) I just got this message saying something like ”legacy boot isn't supported on this computer”. So it seems something changed after I simply put that ”Mac EFI” GPU in and booted into Windows. Hmm…

Now I'm trying to install Windows 10 again (I have started from scratch) so it works as it did before (with my non-flashed GPU), but I'm having trouble – don't remember how I got it to work in the first place… :-/

Edit:
I continued my adventure in this thread: #406

 

[Thessman]

If you still have your windows 10 try using http://www.rodsbooks.com/refind/.