Mac Pro 5,1 with Sapphire 7950 Mac Ed. +GT120 - Fans go crazy

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djbene Author

Level 1

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Mac Pro 5,1 with Sapphire 7950 Mac Ed. +GT120 - Fans go crazy

Hi there,

I was trying hard the last days to get this config working, but I had to give up.

Probably the condensed wisdom here can help me out ...

The situation:

MacPro 5,1, 10.8.4, enough RAM enough HD space etc.

I changed my dual 5770 setup to a Sapphire 7950+GT120 setup (hoping that I could improve further the playout-performance of my TH-S VideoEngine3D software´s four OpenGL screens with the 7950).

After replacing I am stuck now with the problem, that the fans inside the Macpro go to maximum rpm when booting (like in a kernel panic).

The MP itself is running but the noise of the fans is VERY loud ! (those of you who know kernel panics at 5,1 know what I mean...).

Sad to say, this is not a workable solution.

BUT:

When booting and resetting NVRAM, the fans are working as they should. Just after a cold boot the situation with the max fans is back.

So I assume there must be a driver bug somewhere with the NVIDIA card, as without this card the Sapphire and the fans are working normally.

I´m attaching two sceenshots that show the fans (below) after cold boot and booting after NVRAM reset.

Any help would be REALLY appreciated.

Thanks

Bene

Mac Pro, OS X Mountain Lion (10.8.4), Sapphire 7950 Mac Edition

Posted on Jul 28, 2013 4:57 AM

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Answer 1

The hatter

Level 9

60,980 points

Jul 28, 2013 5:05 AM in response to djbene

First thing I would do is remove the GT120. I doubt it is doing enough work to justify having it and at least get to how the 7950 functions on its own.

There are going to be more comments and threads about it here:

http://forums.macrumors.com/forumdisplay.php?f=1&order=desc&page=3

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Answer 2

djbene Author

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Jul 28, 2013 5:17 AM in response to The hatter

Hi,

thanks for your response.

The reason for the GT120 is to have 5 outputs, using the GT120 for the user interface and the four outputs of the 7950 as the playout screens (yes I am using active mDP adapters).

In fact it works, just those crazy fans...

I already searched the macrumors forum but could not get a discussion about this card combination.

As i mentioned the 7950 Mac Edition alone works as it should.

If you have any further ideas where I could have a look for a solution would be gladly appreciated.

Thanks

Bene

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Answer 3

The hatter

Level 9

60,980 points

Jul 28, 2013 5:31 AM in response to djbene

Wanted to be sure the 7950 by itself was okay. So it isn't the card being defective.

I didn't see you say it was working alone as it should. Still don't see it but that is always what I do with new hardware, try it alone.

Didn't realize you needed that many displays.

Would be nice if there were FOUR 6-pin power cables available and use one of the 5770s. Maybe ?

There was/is lots of talk about fan behavior with PC edition cards.

There are problems using any two Nvidia cards but usually AMD + Nvidia have been okay.

NVRAM has uses and is done from cold boot but SMC Reset is better suited.

And just because there have been multiple article changes, hit the power button for 5-10 seconds while all power, all cables, all devices are disconnected.

Is all the RAM the same batch and a full "set"?

Any other PCIe cards? hubs etc

Is it a 6-core or 12-core or what? how much power the system is asking for to boot.

And always nice to protect such a system with 1500VA you can trust too.

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Answer 4

djbene Author

Level 1

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Jul 28, 2013 5:53 AM in response to The hatter

The nice thing in this combinationis is that the gt120 does not need a power cable and is powered enough to drive the user interface of the software.

No PC cards used here.

I tried already any combination of SMC and NVRAM reset, only the NVRAM reset after cold boot leads to normal fan behaviour.

No other PCI cards.

8core 2,4Ghz 5,1

I am in 220V land so enough current is not such a problem.

Thanks

Bene

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