GTX 690 in MacPro4,1 WITH external PSU + Add2PSU

[MyMac1976]

You should read OP's earlier threads to understand. OS X itself will see both GPUs but it will use one. CUDA and OCL accelerated software will see and use both GPUs. That's the point.

I don't disagree with that assessment that will very probably be the case in essence a GUI and CUDA card all on one PCB. One will be under utilized in OSX the other at capacity. I believe his other thread specified he was using Windows only with the 690 but I can't remember. I still would argue that a Titan gives more power and flexibility, for the same price.

 

[5050]

My point was you are going through all of this to put a dial GPU card in a Mac to run Windows. Why not just build a PC and use a KVM switch? Better yet for the same money buy a Titan and use it both OSX and Windows. No dual GPU issue and arguably better performance and more future proof

I'm not running Windows. I'm running OS X and looking to optimize CUDA performance in Adobe After Effects and Black Magic's DaVinci Resolve which are both capable of leveraging multiple GPUs in OS X.

Also, I can't confirm this personally but the Titan is currently unsupported by the current OS X 10.8.3 release and is only rumored to be functional in 10.8.4. The 690 however is supported in 10.8.3.

 

[666sheep]

I don't disagree with that assessment that will very probably be the case in essence a GUI and CUDA card all on one PCB. One will be under utilized in OSX the other at capacity. I believe his other thread specified he was using Windows only with the 690 but I can't remember. I still would argue that a Titan gives more power and flexibility, for the same price.

Both GPUs will be used for CUDA/OCL computing simultaneously.

Judging by benchmarks, I agree that Titan seems better solution. CUDA benchies on Windows are really impressive. GK110 outperforms GK104 by far. Sometimes even twice. http://www.tomshardware.com/reviews/geforce-gtx-titan-opencl-cuda-workstation,3474-15.html
Not to mention its lower power demand.

 

[boodaddyz]

I want to add an external power supply as well. I want to add two 7950's and don't want to chance messing something up by getting adapters for my Mac power supply.

What was your final outcome with this? I read that you had success with the SATA option, but you wanted to run the cables out the back pci slot. Were you able to accomplish this?

I would like to do this as well. Appreciate your time

 

[Korican100]

I am also interested in this, as I think my PS is being overloaded with my 680 and SSD setups

 

[5050]

I want to add an external power supply as well. I want to add two 7950's and don't want to chance messing something up by getting adapters for my Mac power supply.

What was your final outcome with this? I read that you had success with the SATA option, but you wanted to run the cables out the back pci slot. Were you able to accomplish this?

I would like to do this as well. Appreciate your time

Works fine! System and GPU sleeps and shuts down simultaneously and I never have to worry about power issues. I ended up replacing the GTX 690 with a GTX TITAN, but the setup works just the same.

Great part is if I decided to add another TITAN, there's still plenty of power that can be run from the external PSU.

 

[boodaddyz]

Works fine! System and GPU sleeps and shuts down simultaneously and I never have to worry about power issues. I ended up replacing the GTX 690 with a GTX TITAN, but the setup works just the same.

Great part is if I decided to add another TITAN, there's still plenty of power that can be run from the external PSU.

Awesome! Can't tell you how much this helps me. From reading, your final setup was the below. Was this the method you ended up going with?

1) PCIe Mini 6-pin (motherboard female connector)
2) PCIe Mini 6-pin (male) to PCIe 6-pin (male)
3) 6-pin PCIe (female) to SATA 15-pin (male)
4) SATA 15-Pin (female) to Molex 4-pin (male)
5) Molex extension cable (female to female) > Molex 4-pin (male) on Add2Psu

Really appreciate all your time, and help with this!

 

[5050]

Awesome! Can't tell you how much this helps me. From reading, your final setup was the below. Was this the method you ended up going with?

1) PCIe Mini 6-pin (motherboard female connector)
2) PCIe Mini 6-pin (male) to PCIe 6-pin (male)
3) 6-pin PCIe (female) to SATA 15-pin (male)
4) SATA 15-Pin (female) to Molex 4-pin (male)
5) Molex extension cable (female to female) > Molex 4-pin (male) on Add2Psu

Really appreciate all your time, and help with this!

Actually, I ended up going through with my original plan to draw power from the spare SATA 15-pin connector in the 2nd optical bay. The challenge was figuring out how to pass the Molex extension cable from the optical bay into the backplane board (PCIe slots). Eventually I figured out that by removing the nylon housing, I was able to expose the individual 4 pins and thread them easily into the blackplane board. Once that was done, I simply reattached the nylon housing and was good to go. All the other connections fell into place easily.

Here's the final order:

1) Connect SATA 15-pin connection (from 2nd optical drive bay) to SATA 15-pin to Molex 4-pin adapter
2) Connect SATA 15-pin to Molex 4-pin adapter to Molex extension cable (mine was 17" in length)
3) Remove nylon housing from open end of the Molex extension cable to expose the 4 pins (yellow = +12V, black = ground, black = ground, red = +5V). Take careful note of the ORDER of the pins (see attached image, I wrote on the nylon housing to indicate where to reconnect the pins).
4) Pass Molex extension cable from optical bay to backplane board (PCIe slots)
5) Reassemble Molex extension cable nylon housing.
6) Run Molex extension cable out an open PCIe slot (i.e. exiting the workstation)
6) Connect Molex extension cable to Add2PSU.
7) Connect Add2PSU to 24-pin power supply cable.
8) Connect 24-pin power supply cable to external PSU.
9) Run power supply cable connected to GPU out of same open PCIe slot and connect to PSU.

Done! Your Mac Pro and GPU should now work in sync, thanks to the Add2PSU. Sleeps, shuts down, starts up as if running off the Mac Pro's internal PSU. Best part is, depending on your PSU, you might have more power to spare for another GPU!

Here are the cables:

SATA 15-pin to Molex 4-Pin Adapter:
http://www.amazon.com/dp/B003WSY8J6/ref=pe_175190_21431760_M3T1_ST1_dp_1

Molex Extension Cable:
http://www.amazon.com/dp/B003ZDNXYE/ref=pe_309540_26725410_item

Add2PSU:
http://www.amazon.com/Add2PSU-Multi...e=UTF8&qid=1386361884&sr=1-1&keywords=add2psu

Let us know how it works out!