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GPUs with AUX Power Supply (cMP 2010)

kennyman said:
Awesome!! You have dual 7950 GPUs..NICE!!!

Dual X5690 + Dual AMD cards....all you need now is to add a pcie SSD and you are done. BTW, what is your score on luxmark and what is time on BruceX? Any improvement? I have my office mac with dual quadro at the moment (working on some huge 5K files). My single 280X beats both Quadros in Luxmark and BruceX :eek::eek::eek:
Click to expand...

Oh i swap 2x GTX 680 EFI for 2x7950. i was having problem to install windows with dual efi nvidia, did not boot just freeze in white screen with one card at time worked good. I like the games very much in windows and basically i game with many filters at 2560x1440.

my next upgrade will be 2xR9 280X maybe, can you run BootCamp with both cards without freeze in startup?

the bad side is AMD having some problems with Crossfire Mode but it is drivers problem.

here we go with the benchmark
direct export to h264 errors out with code -12348 i can't test with it.

ProRes 422 HQ export to internal SSD drive instead:
FCPX 10.1.2 = 23.36 seconds










 
@Ironjer

Yes, I had some issues booting into Windows or even installing Windows with dual EFI Nvidia cards. But I had the same problem when I tried dual 7970s. However it boots fine with one card, very strange. I think there are some drivers/bugs in the OS on how they load the drivers in bootcamp (I am not very knowledgeable on Windows, will need more testing)

I would highly recommend you to stay with the dual 7950, you would not see a great improvement in moving to dual 280X. I tested dual 280X at stock clock speed, couple of weeks ago, it was 22.xx on BruceX.

You can achieve some improvements by OC-ing the card. But it was not really worth it in a dual GPUs setup, there was no big difference when rendering say a 2 hours video content (it was more or less 5-8 minutes difference). OCing single card helps but not dual setup (not sure how the rendering loads get shared between the 2 cards - does GPU clock speed matters or the number of GPU stream processor?).

But when you OC dual GPUs, there is a lot of heat. So the side panel gets really hot, and the internal fans get louder. But if you lower the GPU clock speed and tune it, it performs well and can even reach/surpass D700.

I would say to wait for drivers on the future OS X releases before upgrading your system, maybe we can install Maxwell top of the line GPUs to do the same thing or just install 290X or 295X2 in the future :D

I would also recommend 1m pcie power cables going forward, mine were really cut to the length, but I have to admit, it can be tricky to go this way.
 
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@kennyman

were the 7970s flashed with EFI too, what kind problem did you have?

my gpus come with boost clock i think is enough not worth overclock it

i hope it too. you imagine Dual 290X running on our mac pro would be a monster
 
Ironjer said:
@kennyman

were the 7970s flashed with EFI too, what kind problem did you have?

my gpus come with boost clock i think is enough not worth overclock it

i hope it too. you imagine Dual 290X running on our mac pro would be a monster
Click to expand...

Yes, both 7970s were flashed, it would worked fine in OS X, either single or dual (ML and Mavericks). But for some reasons, Windows will fail to boot with dual cards (as during Windows boot process it uses some Microsoft drivers to first initialise the cards for video output). And there is the problem to install with dual EFI AMD card, I guess. But I managed to install Boot camp and Windows with one 7970 card only and then install AMD drivers 13.x (old ones), and it worked ok.

Also, I have done some further testing today on OS X, here are my findings;

Bruce FCPX files render to ProRes422 with FCPX 10.1.2

1 x HIS 7970 GHz Edition (GPU clock at 1000 with boost 1050)
27 seconds (3 runs, note the best time)

1 x Gigabyte R9 280X (GPU clock at 1200)
26 seconds (3 runs, note the best time)

Bruce FCPX files render to ProRes4444 XQ with FCPX 10.1.2

1 x HIS 7970 GHz Edition (GPU clock at 1000 with boost 1050)
39 seconds

1 x Gigabyte R9 280X (GPU clock at 1200)
41 seconds

Seems to me that clock speed does not matter a lot now on FCP 10.1.2, but I still recall testing this with the early version FCP X and the OC card will shove off 5-7 seconds. Something is going on here with the latest version of FCP X.

Seems like the app is being optimised to use the stream processing power in parallel (does not matter on the GPU clock), so it uses the GPU processing power but at much lower clock speed to render (950 max I guess). Because when I tried to scale from 1050 to 900 (seconds in rendering were same). Then I went from 900 to 850, results were pretty same, but going from 850 to 800 gave me some weird seconds..and it keep getting worse..which does not make sense at all...maybe there is something in FCP X that tells that card to run at lower speeds or something to do with AMD drivers on cMP (..850-950Ghz max, I have no clue)

So do not OC your card, at least if you are using the latest version of FCP X. There would not be any improvements. Your results are already good, so keep it as it is and enjoy...:)

Yes, 290X or newer cards would be great, more powerful GPU processing power, hopefully with less heat as we shrink the die from 28 nm to...:p
 
What do you think 7950 + 7990 will work?

You imagine them in Crossfire X :eek:

7950 powering by Mac Pro and 7990 powering by aux power supply. :)
 
OOTB it won't work, because there's no device ID in drivers. It could be added manually but even after that it might not work as it should (QE/CI, performace etc).
 
666sheep said:
OOTB it won't work, because there's no device ID in drivers. It could be added manually but even after that it might not work as it should (QE/CI, performace etc).
Click to expand...


Bad news then.

will work at pcie 2.0 in bootcamp?
 
That is a very clean looking dual 7950 install!

Any more details on tapping additional wires off the built-in MacPro power supply for more PCIe power wires?
 
Hello,

I change the title of this thread, it was kind of misleading. I started it for advice on adding powerful GPUs in cMP. But I think it can also help others who want to add Nvidia or AMD card, single or dual:D

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artherd said:
That is a very clean looking dual 7950 install!

Any more details on tapping additional wires off the built-in MacPro power supply for more PCIe power wires?
Click to expand...

Good question, although I do not have a dual AMD card setup, I bought the AUX power for less than USD 25. I did not bother to tap into the power from the PSU. But that would be very interesting...if someone can advise on this :)
 
The MP's power supply is a monster, at 1000 watts it likely has the power to run quad 7950s and possibly quad 7970s (if such could ever be made to fit.)

Transcoding RED RAW 6k (faster than realtime) with my dual 7950s (all powered by the MP internal PSU via combination of included 6-pin headers and Sata power adapters, don't try this with just the 6-pins) produces only 46A total draw on the 12V rail. That's everything. CPUs, FC card, Decklink 4k card, etc. (no HDDs though, just boot SSD and 100TB of fast FC SAN externally) The PSU can output 79A so there's really quite a ton of hardware (and this is with dual 5690s).
 
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I tried to using my FSP Booster aux PSU to help power 2 Titan Blacks (6-pins from the MP, 8-pins from the FSP), but it was a no-go. GPU fans would immediately ramp up to 100% and the machine would hard restart. Never figured out why, so I had to resort to an external PSU sitting on top.
 
riggles said:
I tried to using my FSP Booster aux PSU to help power 2 Titan Blacks (6-pins from the MP, 8-pins from the FSP), but it was a no-go. GPU fans would immediately ramp up to 100% and the machine would hard restart. Never figured out why, so I had to resort to an external PSU sitting on top.
Click to expand...

The TITAN BLACK has TDP of 250W you're using two 500W total. The FSP Booster X5 only can give you 450W max.
 
riggles said:
I tried to using my FSP Booster aux PSU to help power 2 Titan Blacks (6-pins from the MP, 8-pins from the FSP), but it was a no-go. GPU fans would immediately ramp up to 100% and the machine would hard restart. Never figured out why, so I had to resort to an external PSU sitting on top.
Click to expand...

That's strange. Did you ever try powering them exclusively from the FSP Booster with splitters? (safe in that application.) There may be problems with 2 PSUs feeding a single card, voltage rails can move and if they get too far apart, the card can shut down.

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Ironjer said:
The TITAN BLACK has TDP of 250W you're using two 500W total. The FSP Booster X5 only can give you 450W max.
Click to expand...

I very sincerely doubt that is the problem. (It's quite difficult to actually get a card to use 100% of it's TDP, and I bet the FSP Booster X5 can indeed supply 500w before shutting off)
 
artherd said:
That's strange. Did you ever try powering them exclusively from the FSP Booster with splitters? (safe in that application.) There may be problems with 2 PSUs feeding a single card, voltage rails can move and if they get too far apart, the card can shut down.

----------



I very sincerely doubt that is the problem. (It's quite difficult to actually get a card to use 100% of it's TDP, and I bet the FSP Booster X5 can indeed supply 500w before shutting off)
Click to expand...

believe me, it can.

You are overloading the PSU. Remember what the PSU hasn't efficiency of 100% even 80% they need be certified by certification plus.
 
Bad math, folks.

Titans 250 watts includes 75 from slot.

So 2 of them only need 350 watts from cables.

Was FSP triggered?

99% of the "my external PSU won't work with your card" emails are result of no triggering on. Many PSUs have an On switch but still require a signal to supply power.
 
artherd said:
That's strange. Did you ever try powering them exclusively from the FSP Booster with splitters? (safe in that application.) There may be problems with 2 PSUs feeding a single card, voltage rails can move and if they get too far apart, the card can shut down.
Click to expand...
I don't recall honestly. I thought I did. I remember powering them both separately from just the FSP and it working. Interesting thought about the voltage rails if splitting them between two PSUs.

MacVidCards said:
Bad math, folks.

Titans 250 watts includes 75 from slot.

So 2 of them only need 350 watts from cables.

Was FSP triggered?

99% of the "my external PSU won't work with your card" emails are result of no triggering on. Many PSUs have an On switch but still require a signal to supply power.
Click to expand...
Yes, the PSU was triggered. I should add that I was successfully running a GTX 670 4GB and GTX 770 4GB Classified using this PSU before upgrading to Titan Blacks.

I ran the power directly from leads of the main PSU and the 4-pin molex off the spare SATA to trigger, as has been shown in other threads.
 
I have tested dual Titan black`s using the e-Power AUX PSU, I did not have any issues with it. The Titan black is 6 + 8 Pins, no problem with that. I was even able to run heaven benchmark (and I remember it was not that bad at all for a workstation card)
 
Problem solved

artherd said:
That's strange. Did you ever try powering them exclusively from the FSP Booster with splitters? (safe in that application.) There may be problems with 2 PSUs feeding a single card, voltage rails can move and if they get too far apart, the card can shut down.
Click to expand...
Well, it looks like you were on the right track. I tried out the FSP again just now, but this time running both 6+8 pin cables from it instead of using the Mac Pro's two 6-pin ports. It's running fine. I guess the different rail voltages was freaking it out. Now I get rid of this external PSU. Thanks!
 
Cancel that...

Well, spoke too soon.

The machine boots fine with both Titan Blacks powered by the FSP, but when I start rendering with them, no go. In Octane Render, I can utilize either card or both. One card runs fine, but using both cards will cause a hard reset after a few seconds.

My guess is that the first issue was true, the cards didn't like being powered by two different PSUs. But it appears that the FSP (at least mine) also doesn't like powering two Titan Blacks.

Ok, back to the external PSU for me..
 
riggles said:
Well, spoke too soon.

The machine boots fine with both Titan Blacks powered by the FSP, but when I start rendering with them, no go. In Octane Render, I can utilize either card or both. One card runs fine, but using both cards will cause a hard reset after a few seconds.

My guess is that the first issue was true, the cards didn't like being powered by two different PSUs. But it appears that the FSP (at least mine) also doesn't like powering two Titan Blacks.

Ok, back to the external PSU for me..
Click to expand...

Did you try some Windows Stress?
 
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