2x GTX 770 in Mac Pro 5.1

[longname]

Did anyone here try to install 2x GTX 770 in Mac pro 5.1? I want to do so, but I don't know whether I need extra power or not. I heard that Apple Mac Pro PSU is 950W, so it should be enough to run 2 card since GTX 770 just take 225W for each.

 

[Ironjer]

Yes, you need a PSU extra for both card.

 

[flowrider]

The problem is not the PSU, it's the traces on the MOBO.

Lou

 

[h9826790]

The PSU is strong, however, there is no way to safely get all those power from the PSU. I can't even get just few watts from the PSU to my USB 3 card directly.

2 PCIe slot can provide up to 150W safely, and 2 6pin provide another 150W. You still need to find a way to get another 150W to power up both graphic card.

 

[longname]

I just did a quick test, and everything seems to be fine. I purchased a Y Cable PIC 6 PIN(M) to 2x PICE 8(6+2) PIN (F) and then pluged it into the 6 PIN connector. It booted up fine without any problem. I'm a newbie, so please tell me if i'm missing something. Thanks

 

[h9826790]

Yes, it will boot. However, when you stress your machine, your cards will demand the current that double (or may be more) of each 6 pin cable's design limit. That may eventually burn your motherboard if you use this config for a prolong period of time.

 

[Ironjer]

I just did a quick test, and everything seems to be fine. I purchased a Y Cable PIC 6 PIN(M) to 2x PICE 8(6+2) PIN (F) and then pluged it into the 6 PIN connector. It booted up fine without any problem. I'm a newbie, so please tell me if i'm missing something. Thanks

did you try FurMark Stress?

 

[GraniteTheWolf]

Running 1 single card should be perfectly safe. A Gtx 570 uses more power then a 770 and you can safly run a 570 off of stock power. Least that's been the general rule with 570s for as long as i can remember (I have run one for years in multiple mac pros, 1,1/3,1 and now my new 5,1.)

770 vs 570: http://gpuboss.com/gpus/GeForce-GTX-770-vs-GeForce-GTX-570
"Significantly more energy-efficient load power consumption 246W vs 360W" 246watt max load being the 770.

Dual cards you will have no way around needing an aux power supply.

 

[SDAVE]

Just get a GTX780. I got a MacVidCards version and can run any game Max (I rarely game though)...i mostly do production like davinci resolve and need CUDA for other software that requires it.

 

[longname]

Thanks for all of the advice. I think I need an extra PSU to run dual cards.