MP 1,1-5,1 GTX 780 / GTX 980

[MentalVizion]

Hey,

I currently run a GTX 780 under Yosemite (10.10.5). I use two SATA to 6-pin cables to power the 8-pin connector of the 780 to not risk drawing more than the 225W the Mac Pro can provide.
I highly need those two SATA slots now though, leaving me with one of two choices:

1: Connect the 8-pin connector of the 780 using a regular 6-pin to 8-pin cable, thus POTENTIALLY risking to draw more than the intended 225W.

2: Getting a 980 that can be ran with just 2x 6-pin cables. The minimum OS requirement for the 980 seems to be 10.10.5, which I'm running (and planning on keeping for the foreseeable future) anyways.

The 980 requires pre-installed Nvidia web drivers in order to work though. Do the ones I installed for the 780 work for the 980 as well? My guess would be yes, since there's only really the "Quadro/680" drivers anyways, but luckily these seem to work for all the other models as well.

My question: Does anyone have any evidence of a fried logic board etc. because of running the 780 this way? Cause I still couldn't find any... Or would it just make more sense to go for the 980 as it should be pretty much plug and play anyways (at least I hope so in my case)?

I'll be using the GPU primarily for some gaming in bootcamp (Destiny 2 mainly), game dev stuff (Unreal Engine 4, Maya etc.) and video/photo editing (Adobe package)

 

[tsialex]

Hey,

I currently run a GTX 780 under Yosemite (10.10.5). I use two SATA to 6-pin cables to power the 8-pin connector of the 780 to not risk drawing more than the 225W the Mac Pro can provide.
I highly need those two SATA slots now though, leaving me with one of two choices:

1: Connect the 8-pin connector of the 780 using a regular 6-pin to 8-pin cable, thus POTENTIALLY risking to draw more than the intended 225W.

2: Getting a 980 that can be ran with just 2x 6-pin cables. The minimum OS requirement for the 980 seems to be 10.10.5, which I'm running (and planning on keeping for the foreseeable future) anyways.

The 980 requires pre-installed Nvidia web drivers in order to work though. Do the ones I installed for the 780 work for the 980 as well? My guess would be yes, since there's only really the "Quadro/680" drivers anyways, but luckily these seem to work for all the other models as well.

My question: Does anyone have any evidence of a fried logic board etc. because of running the 780 this way? Cause I still couldn't find any... Or would it just make more sense to go for the 980 as it should be pretty much plug and play anyways (at least I hope so in my case)?

I'll be using the GPU primarily for some gaming in bootcamp (Destiny 2 mainly), game dev stuff (Unreal Engine 4, Maya etc.) and video/photo editing (Adobe package)

You can safely use GTX 780 models that have only one 8-pin power input, just use a dual mini PCIe 6-pin to PCIe 8-pin cable. The way you are doing it now is a lot worse than that, since the SATA power can only provide up to 54W.

 

[MentalVizion]

Ok sorry, I apparently got that wrong, it's been a few years
I'm powering the 6-pin on the GPU using two SATA ports, and I'm powering the 8-pin by using a 2x mini 6-pin -> 8pin cable.

I remember back then, it was the general consensus that the mini 6-pins could only provide 75W each, but this seems to be proven wrong now and apparently they're actually able to provide up to 120W without issues as seen in this video?

That still leaves me with the same problem though, as connecting the 8-pin from the GPU directly to a mini 6-pin on the logic board could result in the 8-pin drawing up to 150W (still more than the 120) and it'll ultimately end up in a shutdown anyways.

I guess the 980 just makes more sense. I'm not planning on upgrading the OS anytime soon and I can always just keep the 780 for any potential future hassles regarding the web driver stuff-

 

[tsialex]

Ok sorry, I apparently got that wrong, it's been a few years
I'm powering the 6-pin on the GPU using two SATA ports, and I'm powering the 8-pin by using a 2x mini 6-pin -> 8pin cable.

I remember back then, it was the general consensus that the mini 6-pins could only provide 75W each, but this seems to be proven wrong now and apparently they're actually able to provide up to 120W without issues as seen in this video?

That still leaves me with the same problem though, as connecting the 8-pin from the GPU directly to a mini 6-pin on the logic board could result in the 8-pin drawing up to 150W (still more than the 120) and it'll ultimately end up in a shutdown anyways.

I guess the 980 just makes more sense. I'm not planning on upgrading the OS anytime soon and I can always just keep the 780 for any potential future hassles regarding the web driver stuff-

Your GTX 780 really need the 8pin? My eVGA GTX 680 4GB Classified (8+6 too), the most power hungrier model, works with 6pin + 6pin fine, maybe your could too.
Anyway, a GTX 980 will work better, no doubt, but will limit you to 10.13.6.

 

[edgerider]

my mac vid evga acx gtx780 6 gb has worked flawlessly with one mini six pin to eight pin and one mini six pin to six pin... and it has seen multiple run of 5/6 day rendering at 100%...
so I guess it is safe.

 

[MentalVizion]

Your GTX 780 really need the 8pin? My eVGA GTX 680 4GB Classified (8+6 too), the most power hungrier model, works with 6pin + 6pin fine, maybe your could too.
Anyway, a GTX 980 will work better, no doubt, but will limit you to 10.13.6.

Why will it limit me to 10.13.6? I thought the minimum OS X requirements for a 980 were 10.10.5?
Do you mean just plugging in a mini 6-pin to regular 6-pin cable into the 8-pin connector on the GPU? Does the card even power on then?

my mac vid evga acx gtx780 6 gb has worked flawlessly with one mini six pin to eight pin and one mini six pin to six pin... and it has seen multiple run of 5/6 day rendering at 100%...
so I guess it is safe.

That's good to hear. Do you happen to know whether MVC does other modifications to the card other than the EFI flash? At the very least it's worth a shot I guess. Worst case the Mac should just shutdown if I'm not mistaking.

 

[tsialex]

Why will it limit me to 10.13.6? I thought the minimum OS X requirements for a 980 were 10.10.5?

Limit you up to 10.13.6. NVIDIA web drivers died with High Sierra, no web drivers for Mojave or Catalina. Some Macs have GPUs of the same Kepler generation, so Mojave and Catalina support Kepler GPUs. Apple never released a Mac with Maxwell GPUs, so no support with Apple native drivers at all.

 

[MentalVizion]

Limit you up to 10.13.6. NVIDIA web drivers died with High Sierra, no web drivers for Mojave or Catalina. Some Macs have GPUs of the same Kepler generation, so Mojave and Catalina support Kepler GPUs. Apple never released a Mac with Maxwell GPUs, so no support with Apple native drivers at all.

Oh, ok. I'm a firm believer of "never touch a running system", so I'm fine with that. I see absolutely no reason to upgrade from Yosemite still. Could you elaborate further on your suggestion to use just double 6-pins to power a 780? Do you mean just plugging in a regular ol' 6-pin into the 8-pin socket? Cause I honestly can't imagine that works to be fair.

 

[tsialex]

Oh, ok. I'm a firm believer of "never touch a running system", so I'm fine with that. I see absolutely no reason to upgrade from Yosemite still. Could you elaborate further on your suggestion to use just double 6-pins to power a 780? Do you mean just plugging in a regular ol' 6-pin into the 8-pin socket? Cause I honestly can't imagine that works to be fair.

My card uses more power than yours, it's the most overclocked model from eVGA and works fine with just 6pin+6pin. Anyway, it's a easy thing to test, just install a pair of miniPCIe 6-pin cables and run Furmark. If Furmark works without shutting it down, everything else will work fine.

Yosemite has a lot of quirks, like SIP that don't work, but the problem is that Apple stopped providing Security Updates for it more than two years ago. If you use your Mac for Internet access, the oldest macOS version still supported is 10.13.6 and will probably be supported at least until 10.16 is released around October this year. Firefox and Chrome already removed Yosemite and El Capitan support and announced that Sierra support will be removed this year.

 

[MentalVizion]

A quick question! Could it work, theoretically, if I'd use the dual mini 6-pin to 8-pin cable, and an 8-pin to 6-pin + 8-pin cable? (something like that https://www.ebay.de/itm/Kabel-Y-Ada...460579?hash=item4b3b9977a3:g:7gAAAOSwOFtdF9Lx)

250W (780TDP) - 75W (PCIe) = 175W, if these 175W get drawn and split evenly by BOTH logic board connectors, that would equal 87,5W per connector, far beneath the pretty much proven 120W that can be drawn without problems.

Can this work or am I a little to enthusiastic here?

 

[edgerider]

you absolutely not need that.
just get one mini 6 to 6 and a mini 6 to eight. Mac vid dont change anything powerwise on those card , and mine is a 6gb overclocked version so more memory is more electricity draw.
you’ll be absolutely fine if I am fine.

 

[MentalVizion]

you absolutely not need that.
just get one mini 6 to 6 and a mini 6 to eight. Mac vid dont change anything powerwise on those card , and mine is a 6gb overclocked version so more memory is more electricity draw.
you’ll be absolutely fine if I am fine.

Ok, that's good to hear. I'd still prefer to try the other method though, as it's not really much of a hassle and should be the safer option, provided it works the way I understand.

 

[tsialex]

Ok, that's good to hear. I'd still prefer to try the other method though, as it's not really much of a hassle and should be the safer option, provided it works the way I understand.

You are making wrong assumptions, read my post here where I try to explain how this really works #60, better yet skim all my posts on that thread.

 

[MentalVizion]

You are making wrong assumptions, read my post here where I try to explain how this really works #60, better yet skim all my posts on that thread.

But isn't that exactly what I was trying to ask? Does it have to desperately be an EVGA powerlink? Wouldn't hooking a dual mini 6pin to 8pin -> into an 8pin to 6pin + 8pin work as well? Or does this constellation not distribute power evenly?

 

[tsialex]

Wouldn't hooking a dual mini 6pin to 8pin -> into an 8pin to 6pin + 8pin work as well?

If the ready made cable is wired correctly, yes. It's easier to use a Powerlink than make a correct cable, but if you know how to make one, do it.