Write up on flashing a Gigabyte AMD Radeon 7950

[LightBulbFun]

hello all so I own a Mac Pro 1,1/2,1 that I have upgraded substantially over time and I am always looking to upgrade it when possible. now one thing I have wanted for it was a ATI Radeon 7950/7970/R9 280/X for it as they are the fasted GPUs you can fit to a EFI32 Mac Pro with Boot screens.

so a few days ago I found a Nice 7950 for a very nice price on ebay so I jumped on it. the card in question is a Gigabyte AMD Radeon HD 7950 GV-R795WF3-3GD rev 2.0 http://www.gigabyte.com/products/product-page.aspx?pid=4121&dl=#ov . Now of course this is a PC Card that needed flashing so i was taking a bit of a gamble especially as no one had flashed this card before. so I got the card and popped it into my Mac Pro and it worked in OS X with out Boot screens as i had not flashed it yet but i wanted to verify it worked and played nice with OS X before i flashed it (as these cards where popular with cryptocurrency miners and they get worked very hard doing it so i wanted to make sure mine was not a dud) so i stress tested the card for a while and it passed with flying colours .

now onto flashing it. first I dumped the ROM on the card so i could see whats the most up to date BIOS for this card was. mine had the FX1 series UEFI BIOS on it so I downloaded the latest one from the gigabyte website and then used @netkas excellent ROM creation tool you can find here http://forum.netkas.org/index.php/topic,5619.0.html to make an EFI ROM. I also had to use @Fl0r!an fixrom.py checksum patch. but after i patched it it said it made the ROM with no errors that i could see and indeed an EFI ROM had been made. so I took the ROM and booted into windows and used ATIWinFlash to flash the Card it said it flashed with no errors. (the card has a ROM switch by default its in position 2 which is the one you can overwrite with 1 being the back up) so moment of truth time I rebooted the mac pro and BAM a lovely boot screen greeted me. i was Very happy now and it proceeded to boot into OS X with no issues and the card passed another stress test no issues and as well All the Ports work The 2 mDP the HDMI and the DVI ports are fully functional after flashing. and it works fully still in windows so this is my write up on the Card i dont intend this to be a flashing guide just my experience with the card and knowledge for others if they own the same card and are not sure if it can be flashed or not etc.

a big thanks to @netkas for making the tools and putting in the effort to do so and to @Fl0r!an for his fixrom.py patch.

I hope this helps someone out and that it all makes sense (edited due to typo. meant FX when typed FY)

 

[owbp]

i was taking a bit of a gamble especially as no one had flashed this card before.

No one flashed it?!
Not cool man... (just kidding)

https://forums.macrumors.com/threads/gigabyte-hd7950-rom-observations-power-draw.1966954/

Can't remember what position i was flashing (i think it was 1st) but it actually didn't need fixrom script.
I just copied and pasted EFI part of the Sapphire 7950 Mac to the second part of the Gigabyte's BIOS.

Great GPU btw, I now have MSI TwinFrozr 7950 which is a bit quieter, but Gigabyte was 10C cooler and more powerfull than MSI (not sure if it was just a clock speed or there are some other factors).

Great post and congratulations on beast of the card!

 

[LightBulbFun]

ah very cool! not sure how i missed your thread as i quite heavily researched this card etc to see what others had reported. indeed thats the same card i own (and it will quite happily draw 100W from the 8pin cable the mac pro seems perfectly happy to supply it with such power its not had any issues even with a full 100% load stress test) tho I might look into getting a dual 6 pin to 8 pin adapter and splitting off that to balance the load... indeed the card is a little noisy but i runs nice and cool i rather it run nice and cool then over heat and die on me (esp as AMD cards are not exactly known for reliability and cool running) and i have no problems with the noise not something that bothers me and my music is usually playing louder then it

I did play round with the copy paste route for making the ROM and its quite easy (I tried it before i got the card so i used another rev of rom so when i got the card in hand and saw it was a different rev i just decided to go stuff it and just spend 1 min with the the rom making tool then playing with a hex editor cuz im lazy )

BTW heres its geekbench 4 compute score http://browser.primatelabs.com/v4/compute/120783

 

[owbp]

The power wasn't a real issue, it was just me OCD-ing a little bit too much (not so much on 8 pin draw as on 6 pin being almost idle). With that splitter i could sleep at peace again.

"Noise" was an issue (sort of) because i had Sapphire HD6850 before and it was dead quiet, but believe me - now that i've tried MSI 7950, i would much rather have Gigabyte that is little louder and works at 51C in most demanding tasks, than MSI that is almost as loud but can reach 71C on a hot day.

I was going the HEX route because i can do all in Bootcamp - backup BIOS, edit and flash again. So who's lazy now?
I don't know exact difference, although i remember MacVidCards posting about it, but MSI wouldn't work (EFI part) without the script.

For comparison, just to see that it is weaker, MSI geekbench 4 http://browser.primatelabs.com/v4/compute/2609

 

[h9826790]

The power wasn't a real issue, it was just me OCD-ing a little bit too much (not so much on 8 pin draw as on 6 pin being almost idle). With that splitter i could sleep at peace again.

"Noise" was an issue (sort of) because i had Sapphire HD6850 before and it was dead quiet, but believe me - now that i've tried MSI 7950, i would much rather have Gigabyte that is little louder and works at 51C in most demanding tasks, than MSI that is almost as loud but can reach 71C on a hot day.

I was going the HEX route because i can do all in Bootcamp - backup BIOS, edit and flash again. So who's lazy now?
I don't know exact difference, although i remember MacVidCards posting about it, but MSI wouldn't work (EFI part) without the script.

For comparison, just to see that it is weaker, MSI geekbench 4 http://browser.primatelabs.com/v4/compute/2609

The Hex edit method should always work, unless the chip size is smaller then 128k (e.g. only 64k ROM image can be used).

On the other hard, if the stock ROM image size is > 128K (e.g. 256K ROM), then only the Hex method will work, the script can't handle that.

 

[666sheep]

Re-inventing the wheel could be fun as it can be seen

 

[owbp]

@h9826790
I don't think that's the problem here, since all Tahiti cards have same ROM length AFAIK.
It took me some time to find it (searching here and forum.netkas.org) but i was thinking about this post:

If you started with UEFI version, that is literally all there is to it. Reading all these insane gymnastics you are going through is giving me a headache.

The way to know if it is a UEFI version is if there is code at 65536, if you look in ASCII section the PC UEFI will have "AMD" and "GOP" in leading 1K.

If there is NOTHING after 65536, it is a PC Bios only and you need fixrom.py to remove the "80" from last rom indicator spot (near word PCIR in leading 2K of BIOS)

Once the "80" becomes "00" the checksum has to be fixed to account for that change. That is all that fixrom does.

But if you start with a UEFI for a card with same device id, then last rom indicator is already correct and so are checksum. For those it is literally just copy 2nd half and paste over the UEFI AND SAVE. It couldn't be any simpler.

And that is exactly what i was getting with MSI ROM here and why it worked like a regular PC card after only "hex flashing". Here are both roms, same card.

 

[h9826790]

@h9826790
I don't think that's the problem here, since all Tahiti cards have same ROM length AFAIK.
It took me some time to find it (searching here and forum.netkas.org) but i was thinking about this post:

And that is exactly what i was getting with MSI ROM here and why it worked like a regular PC card after only "hex flashing". Here are both roms, same card.
View attachment 662147 View attachment 662148 View attachment 662149 View attachment 662150

Not really, I did help another guy to create his ROM which is 256k in case. Both he and me didn't realise that, so we failed many times by using the scrip. Until I open my message box, re-read a PM which I ask MVC's suggestion long time ago. His advice was "make sure the ROM is 128k in size". Obviously, he know what I will miss well before it happen. Then we realise that we need to use the Hex method to insert the EFI part, and eventually we successfully create the 256k Mac EFI ROM for his card.

Of course, Hex edit can be tricky if the ROM is non EFI. However, it should always work if do it properly.

P.S. You are partially correct, the ROM length (which contain useful data) of the the Tahiti card is always 64k. However, the chip is not, if the chip is 256k, we still have to make that image 256k in size, otherwise the ROM won't work properly. In his case, we need to put the ROM content in the 1st 64k, then the Mac EFI in the following 64k, and then fill zero in the last 128k (not 100% sure if it's zero only, I did that more then a year ago, can't remember the details) to make the ROM image 256k in size.

 

[owbp]

Thanks, everyday is a good day when you learn something new.
I get it, no matter how long EFI and BIOS parts are, ROM won't work if length is changed, but i really had only experience with Gigabyte and MSI and both were the same size roms, just that one was UEFI and the other one BIOS.

Speaking of that, do you know if all cards have both roms (UEFI and BIOS) on 1st and 2nd switch positions, or does it depends on manufacturer? I've visited many sites (gigabyte, msi, sapphire etc) before buying the first 7950 and almost all of them were saying that position 2 is backup bios (only in case if you mess up the first overclocking).
No-one seems to be mentioning that one is UEFI and the other one is BIOS.

 

[h9826790]

Thanks, everyday is a good day when you learn something new.
I get it, no matter how long EFI and BIOS parts are, ROM won't work if length is changed, but i really had only experience with Gigabyte and MSI and both were the same size roms, just that one was UEFI and the other one BIOS.

Speaking of that, do you know if all cards have both roms (UEFI and BIOS) on 1st and 2nd switch positions, or does it depends on manufacturer? I've visited many sites (gigabyte, msi, sapphire etc) before buying the first 7950 and almost all of them were saying that position 2 is backup bios (only in case if you mess up the first overclocking).
No-one seems to be mentioning that one is UEFI and the other one is BIOS.

AFAIK，there are 3 cases for stock card.

1) The official Mac Edition card - one for Mac EFI ROM, the other is UEFI ROM.
2) Some OC card - one ROM has higher clock frequency then the other one, but same on the UEFI / BIOS part.
3) The 2nd ROM is just the duplicate of the 1st ROM - again, either both UEFI, or both BIOS.

I didn't know a card that come with one BIOS and the other ROM with UEFI yet.

 

[darthgeekonius]

Can you attach the rom so that those who get the exact same card can just flash it?

 

[CapnDavey]

good job man

 

[creepyTowel]

Can you attach the rom so that those who get the exact same card can just flash it?

Can I echo that request? I (thought I) followed the instructions to the letter, but I just can't get a picture with my version. I have the exact same card too. I hope this is possible and thanks in advance.

Thanks

Peter.

 

[LightBulbFun]

is your cards stock BIOS the FY1 Revision?, I dont particularly want to post the ROM, to prevent people from miss flashing cards. (as unlike the PowerPC days its no longer one ROM works for all) (also I never intended my write up to be a flashing guide...)

 

[creepyTowel]

Thanks for the reply LightBulbFun. Yes, mine is the FY1 version. I know you never meant to write a how-to, but what you wrote was so clear that's how it turned out!

 

[LightBulbFun]

Just had a quick look for the ROM. realised that when i made the post i typed FY when I meant to put. FX whoops :/ (those little things that slip you by...) But i will post the FX ROM i actually made and used. and I will also put up an FY ROM I just made for ya. Just a note to anyone use at your own risk. (sorry about the typo)

 

[creepyTowel]

Just had a quick look for the ROM. realised that when i made the post i typed FY when I meant to put. FX whoops :/ (those little things that slip you by...) But i will post the FX ROM i actually made and used. and I will also put up an FY ROM I just made for ya. Just a note to anyone use at your own risk. (sorry about the typo)

That's incredibly kind of you. Thanks a million!

Peter.

 

[hartleymartin]

Would this same process work on a HIS ATI Radeon 7950 HD card that I currently have in my 2008 Mac Pro 3,1?

 

[h9826790]

Would this same process work on a HIS ATI Radeon 7950 HD card that I currently have in my 2008 Mac Pro 3,1?

As long as you create your own rom, yes, it should work. I have a HIS IceQ R9 280, which is equivalent to the HD7950. I can flash it and carry out the R17 mod.

 

[owbp]

AFAIK，there are 3 cases for stock card.

1) The official Mac Edition card - one for Mac EFI ROM, the other is UEFI ROM.
2) Some OC card - one ROM has higher clock frequency then the other one, but same on the UEFI / BIOS part.
3) The 2nd ROM is just the duplicate of the 1st ROM - again, either both UEFI, or both BIOS.

I didn't know a card that come with one BIOS and the other ROM with UEFI yet.

I was thinking about this, sorry for the confusion

Just bought this MSI for myself and saw the thing we were talking a month ago.
What side would you flash, Legacy or Hybrid? I remember MVC talking about this but i can't find that post right now, no matter how much i try...

 

[h9826790]

I was thinking about this, sorry for the confusion
View attachment 670106

Just bought this MSI for myself and saw the thing we were talking a month ago.
What side would you flash, Legacy or Hybrid? I remember MVC talking about this but i can't find that post right now, no matter how much i try...

Looks like you are right, and that's the case 4, UEFI on one side, and BIOS on the other. Thanks for showing me that.

It doesn't matter to flash which one. The Mac will still treat the final product as Mac EFI + Legacy BIOS. However, since the Mac EFI and UEFI cannot exist together in the same ROM. Then it sounds make more sense to dump the legacy BIOS, add the Mac EFI on it, and leave the UEFI untouched. Rather than dump the UEFI ROM, remove the UEFI part, and add the Mac EFI to it. More procedure just means more chance to go wrong.

 

[owbp]

Thank you, was thinking the same thing but i wanted to check with someone else.

 

[Mad Davey]

LightBulbFun,

I have the exact same video card, GV-R795WF3-3GD REV: 2.0 with FX1 bios. I have been trying to use the Netkas script but getting the following error:
ValueError: chr() arg not in range(256)
Then it fails to show the "after"

I have just programmed another card that is identical but is a 7970 and it worked just as it should.

I was wondering if you'd be so kind as to send me you modded bios, I've been beating my head against the wall to find out it wasn't something I was doing wrong since another card programmed smoothly using the exact method. I got two cards on ebay recently one for me and one for wifey, I would like us both to upgrade to Mojave with boot support for windows. Thanks you for posting. I wonder why it would work for you..? You did get your successful after readout? It did spit out a rom for me and I tried it however lost use of mini DP's. For now I put the original bios back and all works well. I am certain I have the correct device ID.

 

[LightBulbFun]

if you scroll up to post 16 I posted my modified VBIOS

as for what I did to get it working @Fl0r!an discovered that the fixrom.py script had a bug in it when used with some VBIOSs and he posted a fix for it so once ya patched fixrom.py it would properly oprate on those VBIOSs which caused it issues before hand, the exact details are on the netkas forums IIRC

I guess this a good time as any to say, im pleased to report that my card is still working fine after 2 years of ownership, now running in a 5,1 and I "R17" modded it a while back with no issues. and now running flawlessly in Mojave 10.14

cant believe its been 2 years since I got the card

 

[Mad Davey]

Oh man, I've been re-reading the netkas thread and not spending enough time on this one! THANK YOU, it was under my nose all this time! You have no idea how much I appreciate this. As a side note, at this point I suspect my dual early samsung U28D590 4k monitors as to why I cannot get the dp outputs going. Its very odd however since with both cards I have, a gigabyte 7970 and a 7950 do not output on the mini dp when modded but both cards work fine unmodded on Mac and PC via mini dp. Frustrating, I need another dp monitor to test my theory and these are all I have atm. Upgrading monitors may be in my future. Let me know if you know I may be missing something for dp output. I'll be giving your rom another try at it, but since my 7970 mod seemed successful I think it may be the monitors. Again thanks! Relatively new to Mac here but not stranger to tweaking hardware and software. I do love our cheesegraters. I'd like to go to Mojave but need stable cards for bootcamp and 4k which was the idea. Downgrading from gtx980... I'm glad I asked you, you sir are a scholar and a gentleman, not necessarily in that order!