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iM 4,1-14,4 2011 iMac Graphics Card Upgrade

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The first post of this thread is a WikiPost and can be edited by anyone with the appropiate permissions. Your edits will be public.
Fl0r!an said:
Having 2 dedicated MXM slots is very good, but it's still possible that you bugger up the ROM so hard that it can't be flashed again without shorting the EEPROM or even exchanging it. Be aware of that.

If you're interested, post your vBIOS here, I'll combine it with the Mac 680 EFI later (or tomorrow).
Click to expand...

i once made a mistake and flashed a renamed zip file instead of the ROM, haha!

still that did'nt brick the card, reflashed it again with normal bios and all was good. or something can go even beyond this kind of accident?
 
Fl0r!an said:
Every PCI ROM will start with 0x55AA followed by the length. When you multiply that length with 512 bytes (or 0x200) you'll get the total length of that ROM. The UEFI or EFI ROM is the 2nd one.
The first ROM usually starts after a short header section (1kg or 1.5kb).

Having 2 dedicated MXM slots is very good, but it's still possible that you bugger up the ROM so hard that it can't be flashed again without shorting the EEPROM or even exchanging it. Be aware of that.

If you're interested, post your vBIOS here, I'll combine it with the Mac 680 EFI later (or tomorrow).
Click to expand...


which of the vBios i should send you? apple legacy, extracted from the firmware update or Dell's stock MXM uefi vbios?


btw, do you know if that header before the rom is important? because i see Dell's one have it and one extracted from Apple firmware does'nt
 
VicLev said:
still that did'nt brick the card, reflashed it again with normal bios and all was good. or something can go even beyond this kind of accident?
Click to expand...
Hehe, yeah it's possible to screw the ROM up in such a way that nvflash won't even let you do a force-flash.

If you leave the PC BIOS alone and only start fiddling with the EFI part the worst thing that could happen is usually that it won't work in a Mac anymore (EFI will crash right at startup, so the Mac won't boot with the card in it). This can be easily fixed in a PC though.

VicLev said:
which of the vBios i should send you? apple legacy, extracted from the firmware update or Dell's stock MXM uefi vbios?
Click to expand...
The stock PC vBIOS of the card you want to flash. Yes, the header is important, I guess the iMac ROMs also have one but it's stored somewhere else (Apple tends to do curious things...)
 
The vBIOS might be somewhere hidden in the ioregistry, but maybe it isn't. I don't know of any one-click utility in OSX which can do a vBIOS dump.

I think the EFI from younger iMacs wouldn't be any help though, it's quite likely they've switched to GOP video drivers instead of UGA video drivers, so the GTX 680 EFI form a MacPro might be a better bet.
 
so you just want to replace the UEFI part from Dell by one from MacPro? or make a hybrid of both? the structure of a mobile vbios seem different from the desktop one...
 
MacVidCards said:
Dude, this is awesome news. I wonder why the other guy who tried it reported no success?

I could more than likely write an EFI rom for it that would enable boot screens and proper monitor support for externals, etc.

Did you take any pics? Could be a major help to others to make this an option.

BTW, you may now be able to install the Nvidia Web Drivers. (They skip machine check if you use a self-init card)

I can't guarantee that Web Drivers will be any better, but if they are worse, you just NVRAM reset to get back to OS X ones.

Please let us know what you did and how you did it.

I'm pretty sure there would be some folks interested in these as an upgrade.
Click to expand...

do you think it's possible to write the vbios distantly? i have access iMac 2011, Dell gtx 780m(and other) GPU and possibility re-flash soft bricked cards in my laptop's 2nd MXM slot? i can test whatever bios you will make.
 
VicLev said:
so you just want to replace the UEFI part from Dell by one from MacPro? or make a hybrid of both? the structure of a mobile vbios seem different from the desktop one...
Click to expand...
Basically yes (some changes both to vBIOS and EFI are needed). That's what I'd do with a usual PC card (works with a MacPro). I can't say how a MXM BIOS differs, never seen one. Can you attach the BIOS of a card you want to flash?
 
Okay, just had a short look: After 1kb Nvidia header the vBIOS follows, then the security cert and the UEFI as last section. I think it would be worth a try to replace the UEFI part with a modified Mac EFI, I can to that later when I come home.

But: Wasn't the GTX 780M the card which didn't work at all in the iMac? Simply attaching a Mac EFI won't enable any OS X display output, this should usually work with the plain PC BIOS thanks to the Nvidia drivers. I can have a look at the display routing table later, maybe it outputs an incompatible protocol (LVDS instead of DisplayPort, or vice versa).
Did you test if external ports work with that card? Did you also try the Nvidia Web Drivers?
 
Fl0r!an said:
Okay, just had a short look: After 1kb Nvidia header the vBIOS follows, then the security cert and the UEFI as last section. I think it would be worth a try to replace the UEFI part with a modified Mac EFI, I can to that later when I come home.

But: Wasn't the GTX 780M the card which didn't work at all in the iMac? Simply attaching a Mac EFI won't enable any OS X display output, this should usually work with the plain PC BIOS thanks to the Nvidia drivers. I can have a look at the display routing table later, maybe it outputs an incompatible protocol (LVDS instead of DisplayPort, or vice versa).
Did you test if external ports work with that card? Did you also try the Nvidia Web Drivers?
Click to expand...

the Mac did boot with this card, OSX loaded, but had no picture on the screen, but i see someone had success with this exact card, maybe indeed the key is in the Nvidia drivers.
 
the 770m though had a limited compatibility: no Bootcamp, no bootmenu, no brightness control and some throttling, any ideas?
 
Bootscreen/Bootmenu can be fixed with EFI, brightness control might be some mismatched mapping in the vBIOS.

Can you upload the ROM of the GTX 770M, too?
 
VicLev said:
http://s000.tinyupload.com/index.php?file_id=89839446327397297760
Click to expand...
Both ROMs (GTX 770M and GTX 780M) have exactly the same display mapping, so I'm a little surprised that one of them works and the other doesn't. Did you try to install the WebDrivers in the meantime? The card should normally work fine unflashed, from my point of view there's little point of EFI-flashing it as long as it doesn't work as PC card in OS X...

Btw, both cards have an LVDS output at index 1. All recent Apple vBIOS files I've looked at (both AMD 6xxx cards and Nvidia 6xx cards) had eDP instead. Why the f*ck does the GTX770M even work at all? :eek:
 
no i have'nt installed the WebDrivers yet, do you have a direct link? seems i can't update, since the system says i am already up-to-date.

Bootscreen is not too important at all, Bootcamp is missing - that's a real problem, together with brightness control and throttling, the last one can be adapted in the vBios clock profiles, i assume.
 
Here we go: I've attached both ROMs with minimal edits. I did not touch the vBIOS part, so chance of bricking should be minimal (if the EFI doesn't work the card will become nonfunctional in the iMac though).
This means, the card will only support 1 display at a time and/or the display might become garbled as soon as the Nvidia driver kicks in (OS X login screen). If everything went fine, you should see a bootscreen though. In this case I'll do the necessary BIOS edits.

Good luck! :)

Download
 
ok, tested both, no bootmenu screen, no bootcamp, no brightness control, this time both work in the OSX desktop enviroment with latest drivers installed.
 
i am looking into the vBios structure now and i am finding that some blocks in the mobile one and desktop are swapped. so you have sewed these two in a bit wrong way, duplicating some of the blocks. could you tell me exactly what you have changed in the 780m vbios? i think i am on to something here!
 
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