slughead

macrumors 68040
Apr 28, 2004
3,104
236
I had a problem with a 1,1 and dual 6870's, I had to boost the PCIe fan speeds in windows before enabling crossfire. It consistently crashed right after boot when I didn't. I tried without the fan speed boost, with, without, and with again. 100% correlation.
 

MacVidCards

Suspended
Nov 17, 2008
6,096
1,054
Hollywood, CA
You might have an issue where Windows has sent display to the other card or a different output, etc.

Whenever I use SLI I always have issues with something like this. If you do the keyboard stuff to complete boot and you can hear normal Windows sound effects, then it is sending display to different place or using wrong resolution.
 

Jani81

macrumors member
Original poster
Feb 12, 2013
42
0
Finland
I tried to boost fan speeds as slughead adviced but it didn't helped at all. Most difficult is the problem after i have booted my mac, pressed alt button and then i choose to boot with windows. Screen just go black after that and nothing happens. I tried to install my windows again with 2 cards but installation also didn't worked when it was supposed to go to windows first time. So i don't hear any windows sounds, screen just stays black and nothing happens after i put my second card in my mac pro. With osx everything works just fine.
 

MacVidCards

Suspended
Nov 17, 2008
6,096
1,054
Hollywood, CA
I tried to boost fan speeds as slughead adviced but it didn't helped at all. Most difficult is the problem after i have booted my mac, pressed alt button and then i choose to boot with windows. Screen just go black after that and nothing happens. I tried to install my windows again with 2 cards but installation also didn't worked when it was supposed to go to windows first time. So i don't hear any windows sounds, screen just stays black and nothing happens after i put my second card in my mac pro. With osx everything works just fine.

Hey, I just recreated your issue.

Try this for me, flip the BIOS switch to just PC BIOS on BOTH cards. (reference 7970 and 7950 have these, even the Mac Sapphire one has it, later boards do not)

Let me know how it goes.
 

Jani81

macrumors member
Original poster
Feb 12, 2013
42
0
Finland
It didn't work. I lost my nerves with this and already sold that card... So next thing what i'm going to buy is gtx780 or ati r290x from you when you get that new radeon working with mac pro. Or do you have any suggestions how to get 7990 working? Or will there be same problems with that card as ati crossfire configurations?
 

Jani81

macrumors member
Original poster
Feb 12, 2013
42
0
Finland
Hey, I just recreated your issue.

Try this for me, flip the BIOS switch to just PC BIOS on BOTH cards. (reference 7970 and 7950 have these, even the Mac Sapphire one has it, later boards do not)

Let me know how it goes.

Hello!

I got my second back from my friend because he didn't have money to pay it. So now i tried your trick but it didn't help. Would it be ok to test to copy some pc bios to my mac 7970 card at windows and then try it again? And what is the easiest way to do it?
 

MacVidCards

Suspended
Nov 17, 2008
6,096
1,054
Hollywood, CA
Do you the know the BIOS switch on back spine?

It is what I have been posting about.

Move it into the other position.

It is near CF connector. Research .
 

Jani81

macrumors member
Original poster
Feb 12, 2013
42
0
Finland
Do you the know the BIOS switch on back spine?

It is what I have been posting about.

Move it into the other position.

It is near CF connector. Research .

I have tried but it didn't help. I don't know why that switch doesn't say anything?
 

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Jani81

macrumors member
Original poster
Feb 12, 2013
42
0
Finland
Now i got windows booting but when it support to log on it gives always blue screen. I have tried to uninstall drivers, install them again etc. Without catalyst drivers windows boot normally.
 

Jani81

macrumors member
Original poster
Feb 12, 2013
42
0
Finland
I have tried it bur after catalyst 13.11 bv8 drivers installation it gives always ablue screen right before windows desktop should be ready. I will try different driver versions next. But this is still some progress. At the begin it didn't even tried to boot at all. I will let you know how this go on. Is there anybpdy else who have tried or using this same crossfire configuration than me? And macvidcards, i really appreciate your help and i will be your customer at future also :)
 

Jani81

macrumors member
Original poster
Feb 12, 2013
42
0
Finland
Not working... Same result with every catalyst versions... I tried also to flash my xfx 7970 card bios from my "mac edition" 7970 pc switch bios. But after that xfx card started to spinning fans with terrible speed and it doesn't boot at all. Any suggestions how i can do bios recovery for that card or do i have to do it with pc? And yes i took copy from xfx original bios before flashing... Now i know how to flash ati cards and i also know what happens when i put the wrong rom in it :D What do you think macvidcards, would it be vice idea to try to flash "mac edition" 7970 pc switch bios from same bios what xfx card have? I have now tried to do everything but it just doesn't work. Power shouldn't be the problem. I have external 520 w seasonic power supply wish i bought from you so i think it's enough for this crossfire configuration?
 

MacVidCards

Suspended
Nov 17, 2008
6,096
1,054
Hollywood, CA
Not working... Same result with every catalyst versions... I tried also to flash my xfx 7970 card bios from my "mac edition" 7970 pc switch bios. But after that xfx card started to spinning fans with terrible speed and it doesn't boot at all. Any suggestions how i can do bios recovery for that card or do i have to do it with pc? And yes i took copy from xfx original bios before flashing... Now i know how to flash ati cards and i also know what happens when i put the wrong rom in it :D What do you think macvidcards, would it be vice idea to try to flash "mac edition" 7970 pc switch bios from same bios what xfx card have? I have now tried to do everything but it just doesn't work. Power shouldn't be the problem. I have external 520 w seasonic power supply wish i bought from you so i think it's enough for this crossfire configuration?

I still can't tell if you understand what I mean by switch.

It is a small electrical switch on card, by the CF connector.

So for instance, to fix your XFX you just place it in other position so it boots from 2nd BIOS, then go into Windows, flip switch back and flash the bad one back.

To clarify, the Reference 7950/70 cards have 2 EEPROM chips. There is a electrical switch that lets you choose which chip's rom you use.

To recover a bad flash, you just flip switch to boot from unmolested BIOS, then BE 100% SURE YOU FLIP BACK.

A card only accesses the chip at boot.

To get CF working I had to be sure that both cards had the EFI switched off and only used the PC BIOS.

This trick worked for 7950 and 7970.
 

Jani81

macrumors member
Original poster
Feb 12, 2013
42
0
Finland
Yes i understand that switch but xfx card doesnt have it. Other card have it and i have plugged it at pc bios position. That's the rom what i flashed to xfx card from other card pc rom. Xfx card have that same place where the switch is at other card but there is no switch. Just similar looking empty place with numbers 1 and 2 like other card have. But without switch. Xfx card is not a "mac edition" card. It's just the normal pc card.
 

AidenShaw

macrumors P6
Feb 8, 2003
18,667
4,672
The Peninsula
thanks

Thank you all for the posts - they reaffirm my position of blocking any Purchase Order from my organization from someone who wants to buy an Apple to run Windows.
 
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