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The Golden Guide to Flashing Graphic Cards


macrumors 68040
Original poster
Jan 17, 2008
The Golden Guide to Flashing Graphic Cards

Update March 2011

Ok, this thread is a bit old, and some things here are no longer important.

For example, you can now generate automatically a 4870 / 4890 firmware in Zeus tool.

I will still leave the old text, it has some important facts.
But you should check out the Zeus thread

For current guides to flashing 4870 / 4890.

For more discussion about flashing, look at

Right now, the two topics in the Macrumors Mac Pro forum with the highest post and view count are "Race to dump the 4870 ROM" and "Ultimate thread: 4890 in Mac Pro". They contain over two thousand replies and have been viewed over hundreds of thousand times.

Both topics are about flashing graphic cards.

In the beginning, the questions that people asked where something like "Heya, I just read the thread, care to explain a little more detailed the Step number three on page 6" or such. Now a days, they are more like "Hey I'm new to this, can you please do everything for me because I cba to read 50 pages, also can you tell me what color of underwear I should wear tomorrow, thanks"

Hey, I dont blame you guys. Actually this is the reason I'm writing this thread. Flashing graphic cards are a hot thing, and with the newly announced Steam for Mac with latest Source games, and upcoming new Mac Pro graphic cards, this trend is not going away. And the only real information is scattered among thousands of posts.

So, let me TRY to summarize this whole thing in one place.
Wall of text, INC.

What, Why and How


What is flashing?
Flashing usually refers to altering or replacing the firmware on a chip.
The graphic card firmware (stored on a chip on the card itself) is data that contains stuff like clock speed, fan control, and more importantly: data for communicating with the computer.

The computer also carries a firmware chip, on the motherboard. The code on this chip is the first code that runs when you start your computer. Amongst other things, it communicates with your computer components (Hey, like the graphic card!).
The firmware on PC computers is called BIOS. BIOS is like 20 years old or something, but moving away from it would be a pain for Microsoft, so they are stuck with it for a while longer.
On Macs however, the firmware is EFI, a successor to BIOS.

So Macs speak EFI and PCs speak BIOS. What does the graphic card speak?
Well, as you may know, there are "Mac Graphic Cards" and "PC Graphic Cards".
The PC cards carry BIOS firmware. So inserting them into a Mac will result in black screen, because the computer fails to initialize them!
So the Mac cards probably carry EFI firmwares, right? Not quite! They actually carry a BIOS firmware with a EFI addition. They are compatible with both! The EFI addition helps the Mac initialize the card, and the rest data, fan speed, clock speed, etc is read from the BIOS portion.

Maybe you are thinking, how can Windows run on Macs if they use EFI? Windows does not support EFI!

Thing is, the Mac can emulate BIOS. This is needed for booting Windows through boot camp. It will not help BIOS Graphic cards to boot OSX.
But! It WILL help PC graphic cards booting Windows. This means that you can use a PC Graphic card in your Mac if you are booting Windows or another OS then OSX. However, since no OSX stuff will run with the PC card, the Bootloader (the list of OS you get when holding alt / option button at boot) will not be accessable when using a PC card. You must select windows in Startup Disk in system preferences
in OSX, then shut down, then insert PC card, and from that point your Mac will act just like a PC.

So, to recap:

PC Cards: Works in PC's, works in Mac when Booting Windows
Mac Cards: Works in PC's, works in Mac when Booting Windows or OSX

You see what the PC cards are missing? Yes, the ability to boot OSX.

And what was it that the PC cards where missing on the firmware? That's right, the EFI addition.

So... maybe it's possible to cut that EFI addition from a Mac Card Firmware, and simply paste it on a PC Card firmware? And it will work in OSX?
Thanks to The Rominator, netkas, and Pipomolo42, we quickly discovered that it was.


Why would you want to run OSX by a PC Graphic Card?

Two words: Price - Performance

Apple does not only charge premium for their computers, but also for their Graphic Cards.
Right now the price on ATI 4870 512mb is $ 349 on Apple Store.
The same card but PC version can be found for $ 130 or less (although becoming more hard to find, because Apple purchased the last 4870 cards before they stopped manufacturing)

Also, while Apple offers the 512MB version only, PC cards are available at double the video Ram, 1GB.
Furthermore, excotic versions of the 4800 series are availbe for PC, like the more powerful 4890.


"How, how how... this seems to complicated, my head is about to explode!! maybe this is something for the hacker guys only"

Sure, if you got that attitude, quit right now. The truth though really is that this **** ain't hard. If you can muster the strenght to read this guide twice, you probably have a 95% success chance.
The more complicated stuff starts right here. So, from the top:

What do you need to flash a PC card to work in a Mac?

1. Power
2. Card
3. ROM (Firmware)
4. A Flashing Tool


The graphic cards today are hungry. The 4800 and 5800 series require two power connectors.
You have two choices for providing these:

1. Using Motherboard Cables

Mac Pro motherboard has two connectors for powering graphic cards. These connectors are special and you will not find the right cable in a PC store.
The cable you are looking for is usually called G5 Graphic Power Cable and can be found on Ebay or ATI.COM store.
These are the cables that is used for Apple's graphic cards. So if you are replacing maybe a x1900, which uses 1 cable, you can use that cable and only have to buy 1 more.
You can also make your own:

2. Using Molex (DVD drive)
On the Mac Pro 06, 07 and 08, the Superdrive bay has two molex power connectors. If you are using only 1 DVD drive, you have a second Molex connector just sitting there. You can use it to power a Graphic Card by attaching several cable converters. I have a guide here:

The connector to insert into the Graphics card usually looks like this:

But some cards have a 8 pin hole instead. Some people have reported that using a 6 pin cable in the 8 pin hole still works fine. Also, there are adapters available:


You can't just pick any PC card and magically have it work in OSX. The cards we have gotten to work are the one closely related to Apple's cards.
Right now, it's the 4870 and 4890.
4850 progress can be found here:

Why not nvidia cards?
Because the rom chip on PC nvidia cards are usually too small to have room for EFI addition. Apple Nvidia cards uses a bigger rom chip.

But there are 1000 different 4870 and 4890 cards! Which manufacturer to choose?

The problem is that the cards made today are very much different from Apple's 4870.
In the beginning, there where 1 XFX card, 1 Sapphire card, 1 MSI card, you get the idea.
Now there are OC version, XXX version, Vapor-X version and alot of other crap.

Those card are very much different from the original Reference 4870 or 4890, both physically and in the firmware.
This makes it hard, and if soon not impossible, to add the EFI addition to these special version cards.

So what you are looking for is a card that is NOT a overclocked version, and does NOT have a wierd looking fan.
(You can always overclock and add a fan to the card later)

Here are the top success cards for 4870 and 4890:

A good idea when choosing a card might be to find another person (or post) of success and track down the ROM (firmware). Because the ROMs are the things you're really going to have to hunt for.

ROM (Firmware)

This flashing thing has been around for a while, so there are tons of Mac Modified roms for PC cards out there (there=this forum)
The ROM is different between card models. One Mac Modified 4870 Rom will not work for all PC 4870 cards.

If there is a XFX 4890 of model ZWFC, it's ROM is going to be different, and possibly incompatible with a XFX 4890 of model ZWFL.
Also, a deeper problem appears. Because the Model itself can have different revisions.
XFX 4890 Model ZWFC Rev. 1.6
XFX 4890 Model ZWFC Rev. 5.4
XFX 4890 Model ZWFC Rev. E.0

Even though they are of same card (4890) of same manufacturer (XFX) of same model (ZWFC), and looks physically the same, the revision can be different and that means the ROM is different.

This is really how specific a ROM needs to be. But if you are lucky, you will find a ROM that is cross compatible. For instance, maybe the XFX ZWFC E.0 ROM will work on a 5.4.
Or maybe even on a different manufacturer, like a Sapphire card.

What you should do is this. Scan all your local and online retailers for cards looking like the ones in the Card Table. Ask the retailer for the Model and Revision (this can be found on a sticker outside the box usually)
Then try the search function to find if anyone else had success with that card.

As Roms can be so individual, it's a good idea to back up your original rom first. You can do so with GPU-Z (google it) in Windows. Click the small green arrow.

There is a small gathering of ROMs for 4890 and 4870 here:

Peloche has made a great 4890 rom table here:

There are also (hundreds?) of roms scattered in the Card threads (Use search function!) - 4890 - 4870

But if your card does not have a compatible Mac Rom out there. What to do?

Well, you could create your own!
Peloche made great instructions of Pipomolos method.
Download this:
Included everything you need for making a 4870 or 4890 rom

If you fail at your attempt, upload your original rom in the right thread and maybe some kind dude will help you out.

So, you have a Mac Modified ROM that is probably going to work for your card. Now what?


Flash Graphic Cards in Windows:

Flash Graphic Cards in DOS:
Instructions are for PC but DOS works on MacPro too:

Flashing Graphic Cards in OSX:

I just finished my new OSX Flashing Tool, Zeus

Now you probably have your PC card up and running in OSX !
All done ?
Nope, there is ONE MORE THING

Excotic cards like the 4890 carries a Device ID that OSX graphics driver does not recognize. To add support, you need netkas QE CI patch.
Without this, the card will run, but at low resolution and no 3D graphics.
These can be installed with Zeus under Driver. Further documentation can be found inside the Help tab.

There you have it

Additional things to know about flashed cards:
For 4870 / 4890 cards:
Only one DVI port is dual link ( supports 30" screens) second is single link.
Cards with other ports then DVI may not work properly, search
Dual displays works under Snow Leopard only.
You can not use VGA ( vga-dvi converter ) on the card.

If you are unlucky, your ROM is so different that it will cause a bug, the "power cable bug". When booting OSX a popup will appear, saying your card does not have enough power. It's just a cosmetic bug, cards works fine, so just click OK.

This works on ALL Mac Pro's

Modding Fan Behaviour

I will probably have to add more to this later...
Also if any info is wrong please correct... May have got stuff wrong.

Last edited:
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Reactions: SubDriver


macrumors regular
Feb 10, 2010
Once again thanks Cindori for taking the time to put all of this together for everyone!


macrumors member
May 10, 2005
Upgrading Mac OSX Graphics Cards!

Hi Cindori,

That was an EXCELLENT write up and very much appreciated! Really you have made something special here and worth a "Sticky" as it saves hours of trying to research the information needed.

Nice work :)


Moderator emeritus
Jun 15, 2000
There are specific links to guides in each forum category where you can post it, immediately above the stickied threads. I'm not referring to the general Guides tab.


macrumors 68040
Original poster
Jan 17, 2008
I know, and they are outdated.

This being a guide and all I still think it serves a greater purpose as sticky then the "Establishing standard benchmark" with it's 26k views and last activity 4 months ago.
Discussion can and will still be made... people are probably still going to ask questions after reading this, just less


macrumors 6502
Mar 7, 2010
This is defiantly make it more clear and easier to understand...

I am really thinking of trying this out, but I am having a hard time (no impossible time) finding cards that look like those in the pic. So how do I know what is good to go with. Newegg has this one, is it a good choice?

Ebay also has a couple, but they look like the new egg one or something other than what is in the pic above.

Should I give it a shot, or just get the official 4870?

Thanks for putting this together!

Dai Bando

macrumors member
Dec 31, 2001
northeast territory
I powered up my xfx4890_ZDFC from the xtra DVD molex, and from the cable from my 1900. I grew impatient with my ATI shipment that never came.
No luck with several xfx rom I downloaded, so I'm looking to see if I can get some (humble pie) help.


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Nov 17, 2008
Hollywood, CA

Should hopefully put an end to the Spoon Feeding requests. ( or at least offer a place to link to when such requests come in)

I hope many people who benefit from your guide and app will find a moment to send you a few Euros for your trouble.


macrumors 68040
Original poster
Jan 17, 2008
thanks, I fixed it

DaiBando, you should try making your own, this guide tells you how


macrumors 6502
Mar 7, 2010
Just wanted to update this to get it back to the top... Very helpful info! :)


macrumors 6502
Mar 7, 2010
I got my card and cables in.

I got a ZSFC v1.6 from newegg...

Going over the steps once more before I begin.. :)
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