fastest gpu 2x6 pin - nvidia 680?

[pastrychef]

Since the other systems in Apple's line up will require drivers for various GPUs, I think it's safe to assume that drivers will continue to progress. For example, the latest iMacs come with Nvidia GTX 700-series GPUs, so they have to include support for them in OS X.

 

[Demigod Mac]

That's a relief to hear. Only big question mark on my mind is the Maxwell (800) series, which are supposed to include an ARM processor onboard, which wouldn't surprise me if it required a significantly rewritten or updated driver... And if the MacPro6,1 external/Thunderbolt video card market has sufficient demand. Or possibly even ones incorporating the proprietary, but replaceable GPUs (I could see OWC or Sonnet getting behind something like this, perhaps) Time will tell.

The latest iMacs (as of 9/24) all have Nvidia GPUs, so I guess that's a good sign of things to come.

 

[djwalter]

It can work, but you will be drawing more power from the Mac Pro's power connectors than they were intended for. 6-pin connectors are rated to draw up to 75W. 8-pin connectors are rated to draw up to 150W. The PCI-e slot is rated at 75W.

As you can see from my post above, my GTX 680 card with two 6-pin connectors are pulling 68.52W and 67.8W from the 6-pin connectors and 63.12W from the PCI-e slot. All are within spec since each of those connections are rated to provide up to 75W.

You can also see that the GTX 780 is pulling 65.76W, 100.2W, and 48.24W. Obviously, 100.2W is above what the Mac Pro's logic board was rated for.

From what I've read it's very possible to run a evga gtx 680 4gb ftw card with just the 2 x 6 pin connectors safely. If that's the case then I won't try to cram in the 5.25 power supply and sell it.

Edit : I think I found my answer according to evga's website max draw 195w, so 75 from each 6 pin and 75 from the pcie slot 225w should be plenty if I'm researching this right?

 

[MacVidCards]

Reality is, even though the card will connect and work with 2 @ 6 pins, the one that plugs into the 8 will draw 110 watts if stressed with Furmark. I have seen this using Hardware Monitor. I do not believe this is anything to worry about, Furmark being a Worst of the worst case scenario.

A GTX285 will do the same and there are no threads about them blowing anything up. GTX 570 will pull 110 watts from both connectors and those have never blown anything up either.

If either of the mentioned cards caused problems, I would know about it.

I found that running a CS6 AE Ray Tracing render used substantially less power than Furmark. Cards all stayed near spec during this. In Windows NVIDIA drivers were changed to detect Furmark and throttle cards down, I believe some 580s self immolated before this was done. They probably didn't bother writing this into Mac drivers since the gear head "wonder what she can do" mentality is rare in OSX. (And getting further snuffed out)

Also, Macs will just shut down when a 580 writes a check that the PSU can't cash. I haven't been able to get a 680 to do this.

 

[djwalter]

Reality is, even though the card will connect and work with 2 @ 6 pins, the one that plugs into the 8 will draw 110 watts if stressed with Furmark. I have seen this using Hardware Monitor. I do not believe this is anything to worry about, Furmark being a Worst of the worst case scenario.

A GTX285 will do the same and there are no threads about them blowing anything up. GTX 570 will pull 110 watts from both connectors and those have never blown anything up either.

If either of the mentioned cards caused problems, I would know about it.

I found that running a CS6 AE Ray Tracing render used substantially less power than Furmark. Cards all stayed near spec during this. In Windows NVIDIA drivers were changed to detect Furmark and throttle cards down, I believe some 580s self immolated before this was done. They probably didn't bother writing this into Mac drivers since the gear head "wonder what she can do" mentality is rare in OSX. (And getting further snuffed out)

Also, Macs will just shut down when a 580 writes a check that the PSU can't cash. I haven't been able to get a 680 to do this.

Thanks for the explanation I don't know if I'll push the card that hard at this point. Stepping up from an 06 to 08 mac pro has my head hurting on trying to choose a video card. Just checking some prices I wonder if the 4g ftw is overkill from the 2gb but from some of the pricing I've found on ebay is it worth it to pay $40 - 50 more for the 4gb.