Fix to prevent the 280X from crashing the MacPro5,1

Hi

I recently bought a 280X and flashed it. All went fine with one exception. Furmark is bringing the machine down because it draws too much power.

The card (in my case a gigabyte windforce rev.2) has a 6-pin and a 8pin connector. Since the macpro has only 2 6-pin connectors one of them is stressed more than the other. This can be observed with HWMonitor or other SMC tools.

So my idea was to distribute the load on both 6-pin connectors. I soldered some wire to connect the 12V lines of each connector.

I did it like this:



Now my machine is not crashing anymore while running Furmark tests.

If the card still draws too much power the OCP would immediately shut down the machine to prevent further harm.

Denis

PS: if you do this you should not use an external PSU with this card anymore! Connecting two different 12V power sources is not a good idea.

I'm very sure I did. But even if not, if both lines were connected booth boosters would show more or less the same value (Ampere) which they did not. After my patch they do show the same value. Also before I soldered the wire I connected both 12V lines through an ampere meter and it showed 2-3A.

I even thought about to solder another wire to the place at the card where the pci 12V line is arriving because the pci line is not that stressed. But I did not find the right place.

The best thing would be if the 6 pin cable and the 8 pin cable has the connection so the graphicscard and the macpro is still unmodified.

Denis

Yes, that should work too. You can check the load with HWMonitor before and after to confirm that it works.

Denis