Titan X and 4,1 / Power

absente

macrumors member
Original poster
Feb 18, 2019
47
4
I want to upgrade the GPU in my mP4,1 flashed to 5,1 and I am considering the older Titan X 12G due to the nice amount of CUDA cores for rendering work and the current low price of just 500USD where I am at.

Now, I am well aware of the Pixlas MOD, however I've seen topics such as this ( https://forums.macrumors.com/threads/titan-x-in-mac-pro.1988491/ )

.. which state that I can drive the card with a 6pin to 6pin and one 6pin to 8pin cable.

It gets even more conflicting - in this topic, people state that "Each PCIe AUX 6 pin connector in the Mac Pro towers delivers 150 watts", however in other topics it's just 75 watts
https://forums.macrumors.com/threads/mac-pro-4-1-and-5-1-pcie-aux-power.2035519/

Can someone who actually has this setup shed some light on wherever I should go the Pixlas route or if an adapter cable would do the job.

PS: Is the apple connector (on the logic port) any different from a PC? E.g., can I simply buy a standart 6pin cable or is it different with apple? Sorry for the noob question.

Thanks a lot,
George
[doublepost=1554320270][/doublepost]After more research it seems like drawing power from two SATA ports for one of the 6pin is safer. EVGA Powerlink is another option. Anyone?
 
Last edited:

tsialex

macrumors 603
Jun 13, 2016
5,612
6,437
Brazil
I want to upgrade the GPU in my mP4,1 flashed to 5,1 and I am considering the older Titan X 12G due to the nice amount of CUDA cores for rendering work and the current low price of just 500USD where I am at.

Now, I am well aware of the Pixlas MOD, however I've seen topics such as this ( https://forums.macrumors.com/threads/titan-x-in-mac-pro.1988491/ )

.. which state that I can drive the card with a 6pin to 6pin and one 6pin to 8pin cable.

It gets even more conflicting - in this topic, people state that "Each PCIe AUX 6 pin connector in the Mac Pro towers delivers 150 watts", however in other topics it's just 75 watts
https://forums.macrumors.com/threads/mac-pro-4-1-and-5-1-pcie-aux-power.2035519/

Can someone who actually has this setup shed some light on wherever I should go the Pixlas route or if an adapter cable would do the job.

PS: Is the apple connector (on the logic port) any different from a PC? E.g., can I simply buy a standart 6pin cable or is it different with apple? Sorry for the noob question.

Thanks a lot,
George
[doublepost=1554320270][/doublepost]After more research it seems like drawing power from two SATA ports for one of the 6pin is safer. EVGA Powerlink is another option. Anyone?
Each PCIe AUX is rated to 75W continuous output.

Power protection cuts the power down around ~130W, maybe a little less.

Some people here use each PCIe AUX successfully at 120W, but this drastically reduce the life of the backplane.
 

riggieri

macrumors newbie
Apr 30, 2012
17
3
I have run a 250w GPU for about 5 years without any power mod. You have to make sure to keep the power supply cool. 43c and I believe it shuts off.

The Fan Control preference pane you find here on the board works great.
 

h9826790

macrumors G5
Apr 3, 2014
12,985
5,863
Hong Kong
I have run a 250w GPU for about 5 years without any power mod. You have to make sure to keep the power supply cool. 43c and I believe it shuts off.

The Fan Control preference pane you find here on the board works great.
The cMP's PSU can easily run above 43C with the native fan profile in warm Aisa.

My dual processor 4,1 PSU run at about 55C after a cold boot. And that's a very clean (dust free) PSU.

So, 43C definitely won't shutdown. However, I agree should keep the PSU cool as much as possible. This is the best way to extend the capacitors' life span.