Sapphire Radeon HD 7950

[macstatic]

That's very good news!
Right now I've removed the HD-7950 card again because I first want to solve the problem of my (probably) partly corrupt cMP BootROM as discussed here. I'm unsure if I can safely reflash the GPU or not if I get a successful boot.

One question comes up about the (original, non-flashed) "Metal" GPU cards:
with Mac-specific GPU cards (like my HD-5870) I can hold down ALT while starting up and I'm presented with the different startup drives I can choose from. I believe this is called the EFI-boot window, right?
But with non-flashed "Windows" type GPU cards (i.e. my HD-7950 Vapor X) I always assumed that the EFI-boot window is still there when I hold down ALT, just that I can't see it with my eyes (the screen is still black).
Is this correct, or is there no way to select a startup drive with non-flashed GPU cards this way?
(The only way to boot into another startup drive then will be to boot into the default drive, then go to System Preferences-Startup drive where you can select the drive of your choice and restart).

It's hard for me to tell because I have booting problems and it makes things like this so much more complicated.

 

[h9826790]

But with non-flashed "Windows" type GPU cards (i.e. my HD-7950 Vapor X) I always assumed that the EFI-boot window is still there when I hold down ALT, just that I can't see it with my eyes (the screen is still black).

Not true, that boot manager need UGA to work properly. For any non UGA card, that will stall, and effectively hang the cMP.

 

[macstatic]

Not true, that boot manager need UGA to work properly. For any non UGA card, that will stall, and effectively hang the cMP.

I'm not sure I understand, and what is UGA?
Are you saying that if I hold down ALT (while booting) with a non-Mac GPU card (i.e. not designed for or reflashed for a Mac) the computer will lock up?
And you then need to turn the power off/on to restart (or hold down the power button for several seconds to do a forced shutdown).

 

[h9826790]

Are you saying that if I hold down ALT (while booting) with a non-Mac GPU card (i.e. not designed for or reflashed for a Mac) the computer will lock up?
And you then need to turn the power off/on to restart (or hold down the power button for several seconds to do a forced shutdown).

Corrrect

I'm not sure I understand, and what is UGA?

From Wiki

The EFI 1.0 specification defined a UGA (Universal Graphic Adapter) protocol as a way to support graphics features. UEFI did not include UGA and replaced it with GOP (Graphics Output Protocol).

UEFI 2.1 defined a "Human Interface Infrastructure" (HII) to manage user input, localized strings, fonts, and forms (in the HTML sense). These enable original equipment manufacturers (OEMs) or independent BIOS vendors (IBVs) to design graphical interfaces for pre-boot configuration.

Most early UEFI firmware implementations were console-based. Today many UEFI firmware implementations are GUI-based.

 

[macstatic]

Aha! I wish I knew that earlier. It was so frustrating to never being able to boot into the startup disk I selected (when I pressed ALT upon startup, waited similarly to when I had the HD-5870 installed), then pressed the left/right arrow keys followed by RETURN in the same manner I had done with the HD-5870 (but now the screen was black), only to experience that nothing ever appeared on the screen. No wonder, as there was no such "select startup disk icon" screen in addition to a black screen!
Then it wasn't all because of a partly faulty cMP BootROM.

So how do you select a startup drive with a non-Mac flashed GPU? Is System preferences-Startup disk the only way to do it with such a card? And what do you do if you've selected the Windows drive as the startup drive, but want to boot back into MacOS? Physically remove the Windows drive, power up the computer while erasing the PRAM (ALT-CMD-P-R) which boots back into MacOS?
That's OK if you only do it a couple of times (i.e. reflashing the GPU), but certainly not for daily use. Maybe there's another way, or people who choose not to flash their GPUs never use another startup drive.

This should really be in a Classic Mac Pro FAQ/Classic Mac Pro beginner info type document. Also the stuff about corrupting the BootROM. Had I known about it before I would have dumped the working BootROM contents to a file ages ago.

 

[h9826790]

So how do you select a startup drive with a non-Mac flashed GPU? Is System preferences-Startup disk the only way to do it with such a card? And what do you do if you've selected the Windows drive as the startup drive, but want to boot back into MacOS? Physically remove the Windows drive, power up the computer while erasing the PRAM (ALT-CMD-P-R) which boots back into MacOS?
That's OK if you only do it a couple of times (i.e. reflashing the GPU), but certainly not for daily use. Maybe there's another way, or people who choose not to flash their GPUs never use another startup drive.

This should really be in a Classic Mac Pro FAQ/Classic Mac Pro beginner info type document. Also the stuff about corrupting the BootROM. Had I known about it before I would have dumped the working BootROM contents to a file ages ago.

I now use OpenCore boot picker.

Before use OpenCore, I use Bootcamp software in Windows, which allow me to select macOS as next boot drive.

How to: Boot Camp without a Boot Screen

I don't remember uninstalling any bootcamp drivers before 6. But I had to uninstall before 6.1

forums.macrumors.com

Or there was a software called Bootchamp, which allow you to boot to Windows once, then auto go back to macOS on the next boot.

BootChamp (Mac)

Restart your Mac and directly access Windows

bootchamp.en.uptodown.com

There are some more solutions like NVRAM reset etc, I don't want to go all of that. What you need now is just flash the HD7950, then use Option boot.

 

[Borowski]

If you need HDMI-connection:
Some variants of 7950/7970/R9 280(X) cards will loose HDMI after flashing (only working w/ Windows or Linux). This is caused by a different sense id and not changeable.

But you can still get HDMI using adapter from DVI or DP.

 

[h9826790]

If you need HDMI-connection:
Some variants of 7950/7970/R9 280(X) cards will loose HDMI after flashing (only working w/ Windows or Linux). This is caused by a different sense id and not changeable.

But you can still get HDMI using adapter from DVI or DP.

Oh, this is a good point, I completey forget to mention that. May be his flashing is successfully, this is why he lost HDMI, and can't see anything on the next boot.

 

[macstatic]

I now use OpenCore boot picker.

Before use OpenCore, I use Bootcamp software in Windows, which allow me to select macOS as next boot drive.

How to: Boot Camp without a Boot Screen

I don't remember uninstalling any bootcamp drivers before 6. But I had to uninstall before 6.1

forums.macrumors.com

Or there was a software called Bootchamp, which allow you to boot to Windows once, then auto go back to macOS on the next boot.

BootChamp (Mac)

Restart your Mac and directly access Windows

bootchamp.en.uptodown.com

There are some more solutions like NVRAM reset etc, I don't want to go all of that. What you need now is just flash the HD7950, then use Option boot.

Are these mostly "hacks"? I've just had my BootROM reconstructed, and there was a warning in the instructions to disable Opencore when dumping the original BootROM contents. I try to stay away from too many non-standard solutions because it complicates things in my experience.

BootChamp on the other hand seems like an ordinary solution within MacOS which could be useful for this.

The Bootcamp software in Windows for selecting MacOS in the next boot sounds useful when you're already in MacOS. I didn't install Windows with Bootcamp, but directly from the installation DVD (after partitioning an entire hard drive in the ExFAT format using Disk Utility in MacOS). Is it possible to add this functionality afterwards? I don't mind having to reinstall Windows 7 on the hard drive if there's a better way.
I should really also have the option to choose startup drive within Windows, so I can boot back into MacOS (if I had forgotten to first do it in BootChamp) so I don't have to physically remove the Windows hard drive.

 

[h9826790]

Are these mostly "hacks"? I've just had my BootROM reconstructed, and there was a warning in the instructions to disable Opencore when dumping the original BootROM contents. I try to stay away from too many non-standard solutions because it complicates things in my experience.

BootChamp on the other hand seems like an ordinary solution within MacOS which could be useful for this.

The Bootcamp software in Windows for selecting MacOS in the next boot sounds useful when you're already in MacOS. I didn't install Windows with Bootcamp, but directly from the installation DVD (after partitioning an entire hard drive in the ExFAT format using Disk Utility in MacOS). Is it possible to add this functionality afterwards? I don't mind having to reinstall Windows 7 on the hard drive if there's a better way.
I should really also have the option to choose startup drive within Windows, so I can boot back into MacOS (if I had forgotten to first do it in BootChamp) so I don't have to physically remove the Windows hard drive.

So far, no evidence shows OpenCore will write anything into the BootROM. That "disable OpenCore" is more a precaution. But I can understand that you want to avoid it.

If you read that post about Bootcamp software. I haven't install Windows via Bootcamp as well. The problem is how to get the correct version of the software now. Users reported that Apple updated the software, which doesn't work anymore.

Anyway, for you, all you need to do is just flashing the 7950. The whole process can be done within 15min.

 

[macstatic]

I used this video and the text below it in YouTube app to flash my 7950. Really easy procedure. After that I have EFI boot and I can choose between Mojave and windows 10

Video uses an MSI Twin Frozr III 3GD05/OC and the UPC label of that card is shown in the video.
(My card is AMD Radeon HD7950 Vapor X,, exactly same procedure)

I've got a 7950 Vapor X as well, but so far haven't been successful in reflashing it. Having bought it second hand I suspect it having been reflashed already (I read that many PC users hack/reflash their GPUs for overclocking and other special features).
One "feature" I've noticed is that one of the two fans just spins for 1-2 seconds while the computer is powered up, then stops. The other fan spins all the time. Does your GPU behave the same way?
Just to make sure we're talking about the same card, mine is a "Sapphire HD-7950 Vapor-X 3GB OC with boost", SKU# 11196-09. Is it the same as yours?

Also, did you reflash yours with the "S" button pushed in (lights up in blue) or out (doesn't light up)?

My plan is to try to figure out which firmware the card came factory installed with and see if it still has that firmware (I suppose the Windows ATIwinflash software that came part of the "bundle.zip" attachement from the HD 7950 etc. flashing guide thread can display it).

 

[macstatic]

So far, no evidence shows OpenCore will write anything into the BootROM. That "disable OpenCore" is more a precaution. But I can understand that you want to avoid it.

If you read that post about Bootcamp software. I haven't install Windows via Bootcamp as well. The problem is how to get the correct version of the software now. Users reported that Apple updated the software, which doesn't work anymore.

Anyway, for you, all you need to do is just flashing the 7950. The whole process can be done within 15min.

Yes, I want to try it again, but right now I'm unsure if my card came with some modified firmware from the previous user or if it actually has the factory installed one.

Which post about the Bootcamp software are you referring to? I read somewhere that with Bootcamp there is some additional software on the Windows side which allows you to boot back into MacOS, so that could be useful.
I'd like to hear more about the version numbers etc. so I can do this properly.

 

[h9826790]

I've got a 7950 Vapor X as well, but so far haven't been successful in reflashing it. Having bought it second hand I suspect it having been reflashed already (I read that many PC users hack/reflash their GPUs for overclocking and other special features).
One "feature" I've noticed is that one of the two fans just spins for 1-2 seconds while the computer is powered up, then stops. The other fan spins all the time. Does your GPU behave the same way?
Just to make sure we're talking about the same card, mine is a "Sapphire HD-7950 Vapor-X 3GB OC with boost", SKU# 11196-09. Is it the same as yours?
View attachment 2153817

Also, did you reflash yours with the "S" button pushed in (lights up in blue) or out (doesn't light up)?
View attachment 2153818

My plan is to try to figure out which firmware the card came factory installed with and see if it still has that firmware (I suppose the Windows ATIwinflash software that came part of the "bundle.zip" attachement from the HD 7950 etc. flashing guide thread can display it).

I never own this actual card, but I owned the other two 7950. Also, helped quite a few guys to flash their card years back (from memory, including this one).

Overclocked ROM etc isn't a problem at all. I also modded the VBIOS before I create mac EFI ROM. This allow me to have boot screen, plus a cool and quiet HD7950. I made all sorts of different 7950 Mac EFI ROM, overclock, downvolt, customised fan profile... The associated Mac EFI has no restriction on this. I tested.

The push button is in or out doesn't matter. It's just a switch to select ROM 1 or ROM 2, the Mac EFI ROM can be flashed into either ROM. As long as the dumped ROM image is 128k bytes.

 

[Borowski]

As i wrote in the other topic: It makes no sense to flash this card w/ any mac-rom.

It has a totally different port-layout, the Hamachi-framebuffer used for reference-HD 7950/7970 won't work. Same problem expected with bootscreen.

 

[h9826790]

Which post about the Bootcamp software are you referring to?

The link in post #81

 

[macstatic]

The link in post #81
View attachment 2153825

Thanks, found your step-by-step guide here.
But I'm a little confused:

• Is this guide about how to install Windows on a separate drive/using the entire drive, but without Bootcamp, yet still including the Bootcamp utilities (allowing to select booting back into MacOS etc. for those who can't choose a startup drive by holding down ALT when starting up)?
• In the start of your guide I read that Bootcamp 6 has some limitations (will only allow you to reboot into your previously used MacOS drive (if you have several different MacOS startup drives you won't be able to select another one). Also Windows 10 doesn't allow installation of Bootcamp 5 software.
  • But if I want to install Windows 7 and am fine with Windows allowing only to reboot back into the latest used MacOS startup drive, is it OK to use Bootcamp 6 for this?
    My Bootcamp assistant in MacOS 10.13.6 is version 6.1.0.
  • Are you referring to just the support software of Bootcamp when referring to version 5? I found the Bootcamp support software 5.0.5033 here
• What does "Brigadier" do? There was no info to be found about this on its download page
  Never mind. "Use Brigadier to download Bootcamp drivers without Bootcamp assistant" explained it. So basically your guide explains how to:
  1. install Windows on a physically separate drive (i.e. not splitting up and creating a partition on your existing MacOS boot drive by using Bootcamp assistant)
  2. Install the Mac-related utilities (drivers, tools to boot back into MacOS etc.) for use in Windows that normally come with a Bootcamp assistant based Bootcamp installation, but this time totally independant of Bootcamp

Is my understanding correct?

 

[macstatic]

In reply to my own question in the previous posting it seems I understood what this was all for correctly, even though I still haven't succeeded in accessing the Apple related software in Windows, but that's for another thread.

May be some lubrication is required. Sounds like the initial "high speed test" is enough to spin up the fan, but once go back to idle, the internal friction is too strong which cause the fan to stop completely.

Great news regarding the fan that doesn't spin up! It actually works after all 👍
After installing Windows 7 on a separate drive by following your step/by/step guide (NOTE: I've added some comments here and onwards in the thread as I've also run into problems when trying to add the Apple drivers and additional software as well as my experiences).

Anyway, I followed Startergo's advice to download and install Windows drivers for this GPU card (download link in my posting below it). That first of all solved the problem of having the previously small square in the middle of my screen as being the Windows desktop to now filling up the entire screen, but the driver also included an additional app (found in the Windows "Start" menu) called AMD Radeon Pro Settings.
If you click on its "Performance" tab in the main section, then click on its "Tuning" tab you'll see a "Fan tuning" part on the right hand side.

So if you click on the "Fan control (%)" switch to turn on manual control, then move the slider at the bottom to something almost 100% followed by clicking the "Apply changes" button at the top right I noticed that the first fan (which has always worked) speeds up considerably, but after a couple of seconds the other fan also spins up.

So indeed, the second fan is working! I assume it means that the firmware tells it to stay still (and silent) until the temperature demands additional cooling. I have no idea if this is the original firmware or the previous owner(s) have added modified firmware to flash themselves, but will look into this before attempting to reflash it again (to get the Mac boot options).

 

[h9826790]

In reply to my own question in the previous posting it seems I understood what this was all for correctly, even though I still haven't succeeded in accessing the Apple related software in Windows, but that's for another thread.




Great news regarding the fan that doesn't spin up! It actually works after all 👍
After installing Windows 7 on a separate drive by following your step/by/step guide (NOTE: I've added some comments here and onwards in the thread as I've also run into problems when trying to add the Apple drivers and additional software as well as my experiences).

Anyway, I followed Startergo's advice to download and install Windows drivers for this GPU card (download link in my posting below it). That first of all solved the problem of having the previously small square in the middle of my screen as being the Windows desktop to now filling up the entire screen, but the driver also included an additional app (found in the Windows "Start" menu) called AMD Radeon Pro Settings.
If you click on its "Performance" tab in the main section, then click on its "Tuning" tab you'll see a "Fan tuning" part on the right hand side.

So if you click on the "Fan control (%)" switch to turn on manual control, then move the slider at the bottom to something almost 100% followed by clicking the "Apply changes" button at the top right I noticed that the first fan (which has always worked) speeds up considerably, but after a couple of seconds the other fan also spins up.

So indeed, the second fan is working! I assume it means that the firmware tells it to stay still (and silent) until the temperature demands additional cooling. I have no idea if this is the original firmware or the previous owner(s) have added modified firmware to flash themselves, but will look into this before attempting to reflash it again (to get the Mac boot options).
View attachment 2158901

If you go this far already. And has the Radeon software to control the fan / clock speed / voltage.

I personally recommend you to find out the minimum stable voltage for your card as well. This can greatly reduce the card's power consumption (for the same performance), and can keep the card cooler and quieter (which can extend the life span of the card)

It's relatively simple for the HD7950, just need some patience.

1) In Windows, download the Unigine Heaven benchmark (free softawre)

2) Run it with Extreme preset (it runs in window mode, this is actually what we want)

3) Reduce the GPU core voltage, 5mV per step (e.g. If your card initial voltage is 1093mV, then make it 1088mV)

3a) Keep doing step 3, for every 10-15s. Every time after you reduce voltage, watch the Unigine Heaven window for 10-15s, make sure no artefacts.

4) At some point, the screen will show artefacts (usually start with small artefacts, but can also from nothing to suddenly very obvious), then add back 10mV (e.g. if artefacts shows up at 928mV, then set 938mV). If your Mac crashed straight away, don't worry, just reboot back to the desktop, and add 10mV to the last stable voltage you recorded).

5) Run whatever GPU stressful test you can do. e.g. Luxmark, Unigine Valley, Furmark... to confirm your HD7950 is stable at that minimum voltage (e.g. in this example 938mV).

Once you find out this minimum stable voltage. When you dump the ROM to create your own Mac EFI ROM for the HD7950. You can use VBE7 (a free software for Windows) to mod the ROM parameters first, then use the modded ROM to create your Mac EFI ROM. So that your card will permanently run at that min stable voltage when under stress even in macOS.

I did this for multiple cards. All of them works extremely well after downvolt. I highly recommend this for HD7950. My first HD7950 stock voltage is 1093mV, and it can actually run stably at 888mV. Very significant improvmenet.

 

[macstatic]

If you go this far already. And has the Radeon software to control the fan / clock speed / voltage.

I personally recommend you to find out the minimum stable voltage for your card as well. This can greatly reduce the card's power consumption (for the same performance), and can keep the card cooler and quieter (which can extend the life span of the card)

It's relatively simple for the HD7950, just need some patience.

Thanks for your instructions.
Yes, I've gotten quite far with the Windows part, but it would be nice to get the Apple related software working. In the meantime I learnt from another posting that (when you want to reboot from Windows back into MacOS but don't have a Mac-specific GPU or a PC GPU which hasn't been reflashed yet) you can simply reboot from Windows, then zap the PRAM (hold the CMD-ALT-P-R keys and don't release until you hear the startup chime again).
I'm not sure, but I think this only works if you have the MacOS startup drive in drive bay 1, so I've moved my MacOS 10.13.6 SSD to there.

I'll look into your instructions for finding the minimum voltage for the card, but I think I'll concentrate on the more important issues first: reflash the GPU (so I can get a Mac boot screen), then see what kind of MacOS environment I'm going to go for (most likely MacOS 10.14 or 10.15, and a vitual machine environment for running my older 32-bit apps in). It's going to be a lot of work, but one step at a time......

As for the voltage tuning -you mentioned reflashing -didn't you mean reflashing the GPU?
If you mean the actual Mac BootROM I'm a little skeptical as I've had so many problems recently with it that I want to leave it alone after Tsialex rebuilt it for me (great job, Tsialex! Highly appreciated and recommended to others with similar issues).

I found the Windows software you mentioned, to prepare for the tuning of the card, just in case others reading also want to give it a try:

Unigine Heaven benchmark
VBE7 (vBIOS editor for Radeon HD-7000 series)
AMD Radeon HD-7000 series Windows drivers w/settings software

 

[h9826790]

As for the voltage tuning -you mentioned reflashing -didn't you mean reflashing the GPU?
If you mean the actual Mac BootROM I'm a little skeptical as I've had so many problems recently with it that I want to leave it alone after Tsialex rebuilt it for me (great job, Tsialex! Highly appreciated and recommended to others with similar issues).

I mean flash the graphic card, not the cMP.

When you create your Mac EFI ROM for the HD7950, you can first mod the original ROM by using VBE7 first (but you need the know the correct number to use, that's why we need to carry out that test to find out the min stable voltage), then create the Mac EFI ROM.

Of course, this part is optional, and you can make that ROM anytime later. As long as you know how to dump, mod, flash the HD7950, you can do that anytime you want.

 

[macstatic]

I mean flash the graphic card, not the cMP.

When you create your Mac EFI ROM for the HD7950, you can first mod the original ROM by using VBE7 first (but you need the know the correct number to use, that's why we need to carry out that test to find out the min stable voltage), then create the Mac EFI ROM.

Aha!
You were referring to the "reflashed for Mac-bootscreen" GPU firmware!
I'm glad I don't need to mess around with the cMP BootROM

So, the reason for having to reflash the GPU firmware with the new voltage settings is because there is no driver/fonfiguration software in MacOS that will keep this?
But if I boot into Windows, I'm guessing this information is stored in the "AMD Radeon Pro Settings" app (see screenshot for the fan settings back in posting #92), so reflashing isn't necessary for Windows use?

Of course, this part is optional, and you can make that ROM anytime later. As long as you know how to dump, mod, flash the HD7950, you can do that anytime you want.

Yes, I think I'll wait until I first find out which firmware is the original factory installed one for my card, and when I've also successfully reflashed it for the Mac bootscreen.

 

[h9826790]

So, the reason for having to reflash the GPU firmware with the new voltage settings is because there is no driver/fonfiguration software in MacOS that will keep this?
But if I boot into Windows, I'm guessing this information is stored in the "AMD Radeon Pro Settings" app (see screenshot for the fan settings back in posting #92), so reflashing isn't necessary for Windows use?

All correct.

 

[macstatic]

I've finally received the original BIOS files for this card from the manufacturer after having searched and tried a variety of others, and have used those to create Mac EFI versions as well.

But I really don't understand if there's something strange going on with my card, if my cables are wrong, if I should use a different BIOS or what.....
I was expecting both DVI outputs to work, but they're not, or at least not consistently.
To other HD-7950 users (and specifically to those with the exact same model as mine: Sapphire HD-7950 Vapor-X 3GB OC with boost): is the behaviour of your card the same?

Two displays, two different DVI cables
I currently only have two DVI cables (and wonder if this might be part of the problem):
display #1 (1920x1200): DVI-D dual link cable
display #2 (1280x1024): DVI-A to VGA cable


Here are the different configurations I've tried, and their results in Windows and MacOS.
("OK" means the desktop is displayed on the screen, "--" means the screen is black/no display):

Original factory-installed GPU BIOS (MacOS 10.13.6 High Sierra)
a) only one display: DVI-I (bottom) output to display #1 (with DVI-D dual link cable): OK
b) only one display: DVI-D (top) output to display #1 (with DVI-D dual link cable): OK
c) both displays attached, like this:
DVI-I (bottom) output to display #2 (DVI-A to VGA cable): --
DVI-D (top) output to display #1 (DVI-D dual link cable): OK (but "Display" system preference tells me both displays are detected even though just one displays anything!!!)

Original factory-installed GPU BIOS (Windows 7)
a) only one display: DVI-I (bottom) output to display #1 (with DVI-D dual link cable): OK
b) only one display: DVI-D (top) output to display #1 (with DVI-D dual link cable): --
c) both displays attached, like this:
DVI-I (bottom) output to display #2 (DVI-A to VGA cable): --
DVI-D (top) output to display #1 (DVI-D dual link cable): --


And now with the same BIOS file, but Mac EFI-patched.
Here the results are the same for both platforms:

Original factory-installed GPU BIOS w/EFI (MacOS 10.13.6 High Sierra)
a) only one display: DVI-I (bottom) output to display #1 (with DVI-D dual link cable): OK
b) only one display: DVI-D (top) output to display #1 (with DVI-D dual link cable): --
c) both displays attached, like this:
DVI-I (bottom) output to display #2 (DVI-A to VGA cable): --
DVI-D (top) output to display #1 (DVI-D dual link cable): --

Original factory-installed GPU BIOS w/EFI (Windows 7)
a) only one display: DVI-I (bottom) output to display #1 (with DVI-D dual link cable): OK
b) only one display: DVI-D (top) output to display #1 (with DVI-D dual link cable): --
c) both displays attached, like this:
DVI-I (bottom) output to display #2 (DVI-A to VGA cable): --
DVI-D (top) output to display #1 (DVI-D dual link cable): --

Could this behaviour have to do with using the wrong cables? Someone suggested that having DVI-D dual link instead of single link can sometimes make a difference (even though I've read that dual link are backwards compatible and the extra pins simply ignored with displays not capable of dual link). Also the DVI-A to VGA cable: could that be the cause of the strange behaviour in MacOS mentioned above with the screenshot (display #2 is black, but both displays appear detected in the "Display" system preference)?

The BIOS that came in the card when I bought it (it's had two previous users) worked with both displays in Windows, but I'm not sure if it did in MacOS, and suspecting that BIOS had been fiddled with I wanted to get the factory installed one before patching it (if a BIOS has been modified I would like to know what kind of mods it has before I start using it).
So using different BIOS files definitely gets different results, and also Mac EFI-patching it makes the results different, but as I really don't know what to expect I would like to hear from other HD-7950 users of their experiences. Is it normal to lose a DVI output? I've heard about lost HDMI outputs (but getting them back again with MacOS 10.14), but not DVI.

 

[Borowski]

Did you flash the GOP-enabler or the netkas-script-modding?

In my opinion: This card is no good choice candidate for adding UGA-EFI w/ netkas-scripting because of a total different port-ids.

 

[macstatic]

Did you flash the GOP-enabler or the netkas-script-modding?

I used the method described in the first posting of the 7950/7970/280/280x Mac EFI flashing thread (and re-written by myself as a step-by-step guide for clarity).
I believe that's the Netcas-script.
I have no idea what the GOP-enabler is. Please explain.

In my opinion: This card is no good choice candidate for adding UGA-EFI w/ netkas-scripting because of a total different port-ids.

Which card are you comparing it to?
Are there different Mac-EFI patching scripts available, for other HD-7950 cards that I can try out?

But it still doesn't explain why I'm not getting any output from the card's DVI-D (upper connector) with the original BIOS, but with another BIOS it does.