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startergo

macrumors 603
Sep 20, 2018
5,020
2,282
But that shouldn't be a problem because i did read online many people with no problem with the card with only the 6pin plugged in.
Some even saying that it worked with any of them plugged in.
So like this it should work anyways no?
All these cards have different power envelopes and requirements. You may be able to use the 6 pin if you modify the power table. Apparently in your case 6 pin can't power through the 8 pin on the card.
 

jonypaul

macrumors newbie
Apr 20, 2019
16
0
All these cards have different power envelopes and requirements. You may be able to use the 6 pin if you modify the power table. Apparently in your case 6 pin can't power through the 8 pin on the card.
Ok so i can't use 2 sata ports, but i can try to use one.
So i just ordered a dual mini 6 pin to 8 pin cable and a sata to 6 pin cable.
This should do the trick no?
I really hope so.
 

jonypaul

macrumors newbie
Apr 20, 2019
16
0
But this way it has all the electric plugs it asks, with all the electrical needs.
Because tgis card only has a 6 pin and a 8 pin connectors
[automerge]1586603965[/automerge]
Sata only provides 54W and the 6 pin requires 75W.
Os gosh, i'm really praying it works.
But i don't understand, i did read people online using this same card only with the 6 pin connected...
 

startergo

macrumors 603
Sep 20, 2018
5,020
2,282
But i don't understand, i did read people online using this same card only with the 6 pin connected...
People are also using Clover on cMP... And here are the results:
People do many, how should I say, not so clever things.
 

Macschrauber

macrumors 68030
Dec 27, 2015
2,979
1,487
Germany
At least 2xmini 6 pin to 8 pin - and another 8 pin to 2x6plus2.

To give load balancing and to power both the 6 pin and the 8 pin.

In theory thats 225 watt max and overloads the board - but imo better than using adapters and blocking sata ports. Plus the danger of cross currents what may flow between sata and pcie Power ports.

Saviest is getting the power from the psu by pixlas mod or alike.
 

jonypaul

macrumors newbie
Apr 20, 2019
16
0
At least 2xmini 6 pin to 8 pin - and another 8 pin to 2x6plus2.

To give load balancing and to power both the 6 pin and the 8 pin.

In theory thats 225 watt max and overloads the board - but imo better than using adapters and blocking sata ports. Plus the danger of cross currents what may flow between sata and pcie Power ports.

Saviest is getting the power from the psu by pixlas mod or alike.
I will try that first then.
Thank you.
In the end if none of them work i can try to connect the power of the power adapter of my windows pc ??
 

MacUser2525

Suspended
Mar 17, 2007
2,097
377
Canada
I will try that first then.
Thank you.
In the end if none of them work i can try to connect the power of the power adapter of my windows pc ??
If you are going to do that you can do the pc power supply not in computer method for it. You can jumper the pins and turn it on without it being in machine.

 

Macschrauber

macrumors 68030
Dec 27, 2015
2,979
1,487
Germany
I will try that first then.
Thank you.
In the end if none of them work i can try to connect the power of the power adapter of my windows pc ??

Its not 100% clear: I mean two mini 6 pin to one single 8 pin. Like this

 

h9826790

macrumors P6
Apr 3, 2014
16,656
8,587
Hong Kong
But that shouldn't be a problem because i did read online many people with no problem with the card with only the 6pin plugged in.
Some even saying that it worked with any of them plugged in.
So like this it should work anyways no?
Any photo? It's hard to know how you powering the card exactly, and hard to know if you do it correctly (or at least in a workable way)
 
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jonypaul

macrumors newbie
Apr 20, 2019
16
0
If you are powering the 8 pin connector with the mini 6 pin alone it will not work. You need to power the 8 pin with 2 mini 6 pins and the 6 pin with 2 SATA to 6 pin cable.
Well, i tried with the 2x mini six pin to 8 pin and nothing, tried to put a 8 pin to 2x 6+2 pin on the tip of that one and the comouter doesn't even start. And unfortunetly i can loose two sata ports on the computer. One i could try but two is too much.
Looks like the only option is sell this card and buy another one.
I did read that the rx580 works without any problems with just a 8 pin.
Is there any specific version/brand of it that is better?
Would it work out of the box with my mac and the macos 10.12.6?
[automerge]1587583123[/automerge]
Its not 100% clear: I mean two mini 6 pin to one single 8 pin. Like this

thanks mate but it was not enough :(
 

startergo

macrumors 603
Sep 20, 2018
5,020
2,282
Is there any specific version/brand of it that is better?
If you gonna buy RX580 I would recommend the reference model:
This card has 2 slots width and does not interfere with a device installed in the second PCIE slot. This particular model has an 8 pin connector. There is an RX-480 with a reference model design which looks exactly the same as this one, but it uses 6 pin connector. I personally have 2 RX-480 reference models, but some people do not recommend them due to excessive power draw from the PCIE slot.
 

jonypaul

macrumors newbie
Apr 20, 2019
16
0
If you gonna buy RX580 I would recommend the reference model:
This card has 2 slots width and does not interfere with a device installed in the second PCIE slot. This particular model has an 8 pin connector. There is an RX-480 with a reference model design which looks exactly the same as this one, but it uses 6 pin connector. I personally have 2 RX-480 reference models, but some people do not recommend them due to excessive power draw from the PCIE slot.
Thanks for the answer.
My budget roght now is about 100€.
So if i buy it would be in second hand.
That's why i would need to know if all of the models are ok and if it works out of the box with the sierra 10.12.6
 

quattro4ever

macrumors member
Nov 25, 2019
38
2
Poland
Hi guys,
I have already done a few changes of the firmware in the graphics card, until today it is still 7950 and there have never been problems, even in cards that had a BIOS switch,
today I wanted to "make" the R9 280X for the first time,
the operation of adding efi itself went ok but after flashing the card nothing has changed, no boot screen, no full card name in OSX,
I switched the switch on the card to another BIOS and repeated the whole operation, this time everything as expected, there is boot screen, name 7950 in OSX :)
maybe my story will help someone

my card is:
Club 3D royalQueen Radeon R9 280X
Screenshot 2020-07-31 at 18.31.44.png
 
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weckart

macrumors 603
Nov 7, 2004
5,976
3,696
I switched the switch on the card to another BIOS and repeated the whole operation, this time everything as expected, there is boot screen, name 7950 in OSX :)
maybe my story will help someone

This is the expected behaviour of all 7950/7970 cards. Switch 1 is the legacy BIOS and is flashable. Switch 2 is the UEFI BIOS and is not flashable.
 

MIKX

macrumors 68000
Dec 16, 2004
1,815
691
Japan
I had an HIS HD 7950 and currently ( my spare GPU ) is a Sapphire dual-X HD 7970. I EFI flashed both cards 9 AND downvolted the 7970.


NOTE : I always have used BIOS SWITCH Position #2

No issues at all.

============================

Power cables for the HD 7970.

TWO x Mini 6 pin - plus - ONE dual SATA to 6 pin.

NOTE : BOTH of the 7970's power sockets must be powered.​

Example : ( this includes including the eVGa PowerLink )
 

PBSCT

macrumors newbie
Jul 19, 2020
6
1
I have a visionTek R9 280X flashed with HD 7970MAC's efi portion. It shows boot screen without any problem. However, it fails to boot my BootCamp windows 10, and gives black screen, while my second-slot working card geforce GT 120 gives error message "Video TDR Failure", and finally the system gets rebooted. I tried to resolve this by following suggestions on youtube, say, to unintall/re-install AMD drivers, set the wifi card to power saving mode, etc, but it still has this problem. The screen is black, and the system get rebooted until letting you change settings/do trouble shooting. The stock UEFI coming with the card works fine. Anyone has this issue? Any advice would be appreciated.

My configuration: Mac Pro 2009 with 2 6-core X5690 cpus, 32GB ram, flashed from 4,1 to 5,1. OS is High Sierra with 140.0.0.0 bootrom/firmware (installed using Mojave installer but without actually upgrading to Mojave as I still would like to use GT 120). BootCamp Windows 10 installed using DVD image (legacy bios) on a separate SSD.
 

PBSCT

macrumors newbie
Jul 19, 2020
6
1
I had the same issue and I managed to find the solution. It is because that Windows 10 wants to verify signature but failed, and therefore refuses to boot. It is easy to fix by disabling enforcing the verification. You can only execute following command in cmd windows (under administration)

bcdedit.exe /set nointegritycheck on

Later on if you want to restore the integrity check, then run following

bcdedit.exe /set nointegritycheck off

The you will be able to boot after rebooting.

By the way, are those Mac7950.rom and Mac7970.rom posted on the netkas are really from MAC edition cards? I am asking this question, because I found there are many settings not following the ROM specification. One example is that the word at 0x2022-0x2023 should be the device ID, which is 0x679A for HD 7950 or 0x6798 for HD 7970. But they are both 0x6708 in the rom file. I checked that no any GPU made by vendor 1002 has device ID 0x6708.


I have a visionTek R9 280X flashed with HD 7970MAC's efi portion. It shows boot screen without any problem. However, it fails to boot my BootCamp windows 10, and gives black screen, while my second-slot working card geforce GT 120 gives error message "Video TDR Failure", and finally the system gets rebooted. I tried to resolve this by following suggestions on youtube, say, to unintall/re-install AMD drivers, set the wifi card to power saving mode, etc, but it still has this problem. The screen is black, and the system get rebooted until letting you change settings/do trouble shooting. The stock UEFI coming with the card works fine. Anyone has this issue? Any advice would be appreciated.

My configuration: Mac Pro 2009 with 2 6-core X5690 cpus, 32GB ram, flashed from 4,1 to 5,1. OS is High Sierra with 140.0.0.0 bootrom/firmware (installed using Mojave installer but without actually upgrading to Mojave as I still would like to use GT 120). BootCamp Windows 10 installed using DVD image (legacy bios) on a separate SSD.
 
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Borowski

macrumors 6502
Oct 22, 2018
254
72
Do you mean the efi-part or header? Post a screenshot please, if possible.
The script will correct the dev-id before compressing, the vendor-id will always remain 0x1002 (=AMD/ATI). The efi is from the "real" mac-edition-card 7950.
 
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