NVDIA GPU for Mac Pro 3.46GHz CPU's

[Dr. Stealth]

Dr. Stealth

How do you power 2 GTX 1080 Tis in your Mac Pro

I run a 450w aux PSU in the lower optical bay. I have it's power tied into the stock PSU so it turns on when I turn on my mac. It was a pretty simple upgrade I did about 4 years ago and I've never had any issues powering any GPU since.

I have to add... This was one of the best 'bang for the buck' upgrades I've ever done to my cMP. Cost was about $75.00

1. Never worry about drawing too much power from your cMP motherboard or PSU.
2. Never worry if your cards are getting enough power.
3. No unsightly external wires or PSUs.
4. Use even the highest draw cards (fastest) without issues. The combined TDP of my three GPU's is 610W.
5. Take a load off your poor mac PSU giving it lots of overhead.

 

[Flint Ironstag]

Yes, sorry I guess I misunderstood you. I have no heat issues while running two open-air GPU's that can draw up to 280W each. Also in slot 2 I have a Amfeltec PCIe Board with Dual SM951 512GB SSD's. They also produce quite a bit of heat. I am running an Apple GT-120 blower style card in slot 3 so I imagine that helps to some degree to exhaust the PCIe chamber.

So, we know the hot air is getting out. You're just curious as to how it's getting out. It would be interesting to see a smoke test done to follow the airflow.

Cheers !

Maybe one day Apple will divulge the parameters which shaped the case design. I'm pretty sure the high end (hot), officially sanctioned Apple GPUs have blower style fans. For multi-card, sustained computational loads I go OEM, blower design only.

Makes me wonder what type of cooling solution my theoretical "Lisa" will have. Nvidia claim their DGX machine learning workstation is quiet, so surely Apple can pull it off.

o do not all macs come with that port? gess im out of date on new computers >.< ill check next time.

Was just lamenting this in another thread. Apple has been doing this for a while. First it was with FW ports, now Thunderbolt. Needs to be on every. single. machine. in the lineup.

Back On Topic:

I didn't see where OP specified which apps they'll be using. This can affect our recommendations.

 

[orph]

@Gios93 if you want to compare cards may be simpler to just look at GPU reviews that cover what you want to do with the card.
if you want to game look at gaming reviews, compute compute reviews in the app's you need/want etc...

if driver support is important the GTX680 is the fastest nvidia with official apple support and a PC card can be flashed with a mac bios which makes it the cheep option, next are MVC nvidia cards which he custom flashes with mac ok bios (not official apple support but MVC works out how to make them work).

i have used a PC GTX660 & GTX770, the 770 is faster

i assume the best nvidia is a MVC flashed titan X

 

[Dr. Stealth]

Maybe one day Apple will divulge the parameters which shaped the case design. I'm pretty sure the high end (hot), officially sanctioned Apple GPUs have blower style fans. For multi-card, sustained computational loads I go OEM, blower design only.

Makes me wonder what type of cooling solution my theoretical "Lisa" will have.

It wouldn't take much to see exactly how the cMP moves it's air. The cool thing is you could use your cMP to do all the calcs.

1. Build a simple cMP case (CADD Model) including the internal partitions and fan assemblies. (or download from GrabCad)

2. Set up a Flow Analysis Simulation using ANSYS. Bingo... You have your answers. After all this is exactly how Apple Engineers designed the case in the first place. They don't just guess how its going to work or hope it works. They know exactly how it's going to work long before manufacturing ever begins. It'd be interesting to see.

 

[NY Guitarist]

I run a 450w aux PSU in the lower optical bay. I have it's power tied into the stock PSU so it turns on when I turn on my mac. It was a pretty simple upgrade I did about 4 years ago and I've never had any issues powering any GPU since.

I have to add... This was one of the best 'bang for the buck' upgrades I've ever done to my cMP. Cost was about $75.00

1. Never worry about drawing too much power from you cMP motherboard or PSU.
2. Never worry if your cards are getting enough power.
3. No unsightly external wires or PSUs.
4. Use even the highest draw cards (fastest) without worries or issues. The combined TDP of my two cards is 560W
5. Take a load off your poor mac PSU giving it lots of overhead.

I'd like to do this with a 5.1 machine too, and would love to have a link to the kit you used. I'm mostly looking to buy a proven 'kit' rather than having to figure out which pieces I would need and how to connect to the stock PS like your set up.

Any info would be greatly appreciated.

 

[fendersrule]

Found some good discussions about the heat dissipation in the 5,1 Mac Pro in this thread.

I'm curious on Dr. Stealth's take. As far as I know, there is no active cooling for the PCI-E slots. The fan that's in the Mac Pro blasts the CPU(s) which is under the PCI slots (and separated to some extent). Warm air rises. There is no fan, or anything up top to bring it out faster. But somehow that enough heat escapes somewhere, without a fan.

I'm wondering for those of us who are just running 1 GPU, can we get any type of GPU cooler, or should we still stick to reference to be safe? I've always thought that cMP's should gravitate towards blowers instead of multi-fan coolers, but it sounds like for 1 GPU it perhaps doesn't matter?

 

[h9826790]

Found some good discussions about the heat dissipation in the 5,1 Mac Pro in this thread.

I'm curious on Dr. Stealth's take. As far as I know, there is no active cooling for the PCI-E slots. The fan that's in the Mac Pro blasts the CPU(s) which is under the PCI slots (and separated to some extent). Warm air rises. There is no fan, or anything up top to bring it out faster. But somehow that enough heat escapes somewhere, without a fan.

I'm wondering for those of us who are just running 1 GPU, can we get any type of GPU cooler, or should we still stick to reference to be safe? I've always thought that cMP's should gravitate towards blowers instead of multi-fan coolers, but it sounds like for 1 GPU it perhaps doesn't matter?

In my own test, a good bower type GPU work best (like this one). But open fan type also work, not that easy to overheat at stock speed /voltage, modern GPU has very good throttling.

However, it's clearly that leave the side panel open can let the open fan type graphic card run cooler (about 3-5C). So, I believe that the cMP doesn't has good PCIe compartment cooling.

 

[ActionableMango]

Speaking for the 4,1 and 5,1, the cMP is compartmentalized in three zones. The top zone (optical drives and power supply) is cooled by the power supply fan. The middle zone (PCIe and 3.5" drives) is cooled by the PCIe fan. The bottom zone (CPU) is cooled by the front and rear case fans.

There are definitely exit holes in the middle PCIe area:

If there were no exit holes in the PCIe area, then there would be nowhere for the PCIe fan blowing in at the front to exhaust out. A blower card would certainly help, but you can see in the example above that there are Apple GPUs with no exhaust ports, so they clearly don't rely on GPU exhaust ports.

This case design itself has no issues with cooling--there are half a dozen fans and holes literally everywhere. There are some cooling problems, but they are related to SMC bugs.

 

[h9826790]

It wouldn't take much to see exactly how the cMP moves it's air. The cool thing is you could use your cMP to do all the calcs.

1. Build a simple cMP case (CADD Model) including the internal partitions and fan assemblies. (or download from GrabCad)

2. Set up a Flow Analysis Simulation using ANSYS. Bingo... You have your answers. After all this is exactly how Apple Engineers designed the case in the first place. They don't just guess how its going to work or hope it works. They know exactly how it's going to work long before manufacturing ever begins. It'd be interesting to see.

View attachment 715023 View attachment 715024
View attachment 715025

This sounds easy, if we know the exact dimensions of everything inside the cMP. Otherwise, I can imagine just to build a accurate 3D model is already a big project

 

[xactoman]

I have an EVGA GTX 1080 in my cMP. the card has a dual fan cooling setup that exhausts out the backside of the card. This along with the PCIe exhaust fan keeps it plenty cool. There is a TON of hot air coming out the back. cMP has dynamic cooling, if it gets too hot, fans go up and move the hot air out. I wouldn't worry about cooling on a cMP unless you turn it on and the fans are going full bore constantly. Its basically open front to back.

 

[ActionableMango]

Having switched back to a Windows PC a few months ago, I have to say that ATX is a mess. Everything just seems so random. There's vertical airflow, horizontal airflow... heck, my power supply is upside down and has 90 degree airflow. There are spots for fans with no fans mounted. Cables all over the place. Drives all over the place. Optical drive coming out the back??? Lots of little different size screws. It goes on and on. There is no integration at all.

I miss the elegance of the cMP. It was just the right blend of proprietary design and industry standards to suit my particular preferences.

 

[irked]

Having switched back to a Windows PC a few months ago, I have to say that ATX is a mess. Everything just seems so random. There's vertical airflow, horizontal airflow... heck, my power supply is upside down and has 90 degree airflow. There are spots for fans with no fans mounted. Cables all over the place. Drives all over the place. Optical drive coming out the back??? Lots of little different size screws. It goes on and on. There is no integration at all.

I miss the elegance of the cMP. It was just the right blend of proprietary design and industry standards to suit my particular preferences.

I've been watching "Halt and Catch Fire" lately, and every time they say "Hardware is forever" i smile at my cMP.

 

[Dr. Stealth]

I fully agree with ActionableMango. In fact I stole his graphic. =) (Thank You Sir)

After all the talk about the PCI area airflow I had a close look at the case. The Optical/PSU chamber is clearly separate from the lower two areas. The rib in the door that secures the door latch closes it off completely. However the PCI area and the CPU area are not sealed from each other. There's about a 1/4" gap that runs 16" long inside the door. It's not by accident, it's by design. That's 4 square inches of open space that allows the Main Exhaust Fan in the CPU area to pull air from the PCI area. That plus all the holes in the back of the case. It's not a cooling mystery, just good old fashioned engineering.

 

[h9826790]

I fully agree with ActionableMango. In fact I stole his graphic. =) (Thank You Sir)

After all the talk about the PCI area airflow I had a close look at the case. The Optical/PSU chamber is clearly separate from the lower two areas. The rib in the door that secures the door latch closes it off completely. However the PCI area and the CPU area are not sealed from each other. There's about a 1/4" gap that runs 16" long inside the door. It's not by accident, it's by design. That's 4 square inches of open space that allows the Main Exhaust Fan in the CPU area to pull air from the PCI area. That plus all the holes in the back of the case. It's not a cooling mystery, just good old fashioned engineering.

View attachment 715371

I agree that the Exhaust fan helps to pull the hot air out. However, by considering hot air rise, it doesn't looks like an effective way to cool down the PCIe compartment. That gap between the CPU / PCIe compartment sure large enough for air to exchange, but seem not good for convection. Of course, may be Apple don't want any convection at there to disturb the airflow. But if good convection is not there, the hot air in PCIe compartment is hard to get into the CPU compartment and then push out by the exhaust fan.

Anyway, if looking from the inside, it is like this.

Only the holes in the red area is available for exhaust (I add the holes on the PCIe slot myself, they are not there natively). Much less then what we look from the back.

Again, I am not arguing the cMP will overheat. I am very happy with my cMP. I just believe that the cooling can be better. But as you said, air is very "fluid", those holes in red area may be more than enough already, as long as the PCIe fan work properly. And with the help (or as backup) from the Exhaust fan. The hot air should able to get out at a reasonable rate.

 

[Dr. Stealth]

I agree that the Exhaust fan helps to pull the hot air out. However, by considering hot air rise, it doesn't looks like an effective way to cool down the PCIe compartment. That gap between the CPU / PCIe compartment sure large enough for air to exchange, but seem not good for convection. Of course, may be Apple don't want any convection at there to disturb the airflow. But if good convection is not there, the hot air in PCIe compartment is hard to get into the CPU compartment and then push out by the exhaust fan.

Anyway, if looking from the inside, it is like this.
View attachment 715373
Only the holes in the red area is available for exhaust (I add the holes on the PCIe slot myself, they are not there natively). Much less then what we look from the back.

Again, I am not arguing the cMP will overheat. I am very happy with my cMP. I just believe that the cooling can be better. But as you said, air is very "fluid", those holes in red area may be more than enough already, as long as the PCIe fan work properly. And with the help (or as backup) from the Exhaust fan. The hot air should able to get out at a reasonable rate.

If you do not understand how the Mac Pro cooling functions that only places you in the general public. It does not mean there is a deficiency in the cooling. It only means you do not understand modern manufacturing/engineering. The fact that there is no overheating in the Mac Pro case is the evidence.

 

[h9826790]

If you do not understand how the Mac Pro cooling functions that only places you in the general public. It does not mean there is a deficiency in the cooling. It only means you do not understand modern manufacturing/engineering. The fact that there is no overheating in the Mac Pro case is the evidence.

I think it's the 3rd time I emphasis that I don't think the Mac Pro has deficiency in cooling, but just "can do better". My argument is, a proper designed case, open the side panel should decrease cooling performance, but on the cMP, it's the other way around. This is an evidence that the hot air in PCIe compartment unable to get out effectively (I say again, it's nothing to do with overheating, but just can do better).

And I am entirely a general public in computer case deign / cooling. Even the above agreement "computer should cool better with side panel closed" is just the concept I learn from google. Not necessary the truth.

Anyway, there is no doubt that we all agree there is no overheating issue on the cMP. I just enjoy to study it more.

 

[Dr. Stealth]

I think it's the 3rd time I emphasis that I don't think the Mac Pro has deficiency in cooling, but just "can do better". My argument is, a proper designed case, open the side panel should decrease cooling performance, but on the cMP, it's the other way around. This is an evidence that the hot air in PCIe compartment unable to get out effectively (I say again, it's nothing to do with overheating, but just can do better).

And I am entirely a general public in computer case deign / cooling. Even the above agreement "computer should cool better with side panel closed" is just the concept I learn from google. Not necessary the truth.

Anyway, there is no doubt that we all agree there is no overheating issue on the cMP. I just enjoy to study it more.

 

[pierrox]

I run a 450w aux PSU in the lower optical bay. I have it's power tied into the stock PSU so it turns on when I turn on my mac. It was a pretty simple upgrade I did about 4 years ago and I've never had any issues powering any GPU since.
View attachment 714749

That was a great option, but unfortunately it's no longer available - in fact, it was discontinued years ago. No one makes 5.25" PSU these days - or at least, no one that can be easily found with 15mn of web search.

 

[Mustard Seed]

I recently upgraded from dual (flashed) GTX 680 4GB to dual (un-flashed) GTX 1080 TI's. I do mostly CAD design and rendering and needed the most CUDA cores I could get. I was always happy with the 680's and never had a problem with them but the 1080's are smoking fast for rendering. Basically cut my render times to about 1/4th the time of the 680's. A one hour render now takes 15 minutes. I have a GT-120 installed for boot screens if needed.

Dual EVGA GTX 1080 TI FTW3's

View attachment 714468 View attachment 714469

Are you on Sierra, using the latest Nvidia web drivers with beta Pascal support?

I'm on Sierra running two 780s in an eGPU box currently, and haven't been reading a lot of positive reviews of 1080s on Sierra. I'd love to upgrade to Pascal too!

 

[Dr. Stealth]

Are you on Sierra, using the latest Nvidia web drivers with beta Pascal support?

I'm on Sierra running two 780s in an eGPU box currently, and haven't been reading a lot of positive reviews of 1080s on Sierra. I'd love to upgrade to Pascal too!

Yes, Sierra 10.12.6 with...

 

[NY Guitarist]

That was a great option, but unfortunately it's no longer available - in fact, it was discontinued years ago. No one makes 5.25" PSU these days - or at least, no one that can be easily found with 15mn of web search.

I searched for far longer than 15 minutes and came up empty. That particular Aux-PS was an ideal solution!

 

[Mustard Seed]

Yes, Sierra 10.12.6 with...

View attachment 715474

View attachment 715478

Thanks for the info! Here's my Octanebench on the 780s. Seems like about a 2.5x speedup if I were to go for it! Would you know if Sierra could support x4 1080ti's? My eGPU case has the space and PSU to support it.

Thanks again!

 

[OS6-OSX]

Anyway, there is no doubt that we all agree there is no overheating issue on the cMP.........

Is this the UFO section of this thread? I took a photo of this. Well, now that I look at it again it's just the fan I have blowing across my PCIe cards for additional cooling/air flow! That was pretty scary for a moment.

 

[Dr. Stealth]

That was a great option, but unfortunately it's no longer available - in fact, it was discontinued years ago. No one makes 5.25" PSU these days - or at least, no one that can be easily found with 15mn of web search.

Yes, I've looked for them recently and found them pretty hard to find. But not impossible. I just did a quick search and found a brand new one on Amazon. Not the same brand as mine but looks nearly identical and it's 450w, same as mine. Ad say's (1) available, if it's true someone need's to snatch it up !

 

[Squuiid]

Yes, I've looked for them recently and found them pretty hard to find. But not impossible. I just did a quick search and found a brand new one on Amazon. Not the same brand as mine but looks nearly identical and it's 450w, same as mine. Ad say's (1) available, if it's true someone need's to snatch it up !

View attachment 715722

What are people's experiences with this thing? This review utterly destroys it:
https://m.hardocp.com/article/2011/01/24/epower_juice_box_450w_auxiliary_power_supply_review/9