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vanlam

macrumors newbie
Original poster
May 30, 2015
5
1
Assuming it works (same power draw as GeForce GTX Titan X, so I don't see why it wouldn't), the 980 Ti should be a really nice card for the old Mac Pro:

74790.png


Full review at Anandtech: http://www.anandtech.com/show/9306/the-nvidia-geforce-gtx-980-ti-review
 

placidity44

macrumors 6502
May 20, 2015
367
166
WOW! My pc build I sold had 2 680's in SLI and a 980Ti has all that power. Moore's law is remarkable and fascinating. If it's compatible you're in for one heck of a treat. Best of luck to you!
 

Zorn

macrumors 65816
Feb 14, 2006
1,115
787
Ohio
Since this card has a 6-pin & 8-pin connector, doesn't it require an external PSU, or a hack that may not be safe long term?
 

fuchsdh

macrumors 68020
Jun 19, 2014
2,021
1,820
Since this card has a 6-pin & 8-pin connector, doesn't it require an external PSU, or a hack that may not be safe long term?

You could run the extra power off your SATA ports or optical drive. Would take some cabling, but that's eminently doable.
 

netkas

macrumors 65816
Oct 2, 2007
1,198
394
Just one thing about 980ti is worrying.

Best binned chips go to titan X.
980ti getting the rest, and some of these chips require higher voltage. In one review I saw a sample running at 270-280 watts tdp, 30 watts more than TitanX. It's rare but could happen, and such card could be a no go for macpro.
 

lowendlinux

macrumors 603
Sep 24, 2014
5,446
6,762
Germany
According to the reviews, this card comes within about 3-4% of the performance of the Titan X, which is a $1000 GPU. Considering that, the price is actually very reasonable.

The issues is the x80 and x80Ti keep getting more and more expensive through the generations. I do agree that it's a budget Titan but that's not saying all that much either.
 

Demigod Mac

macrumors 6502a
Apr 25, 2008
838
288
Just one thing about 980ti is worrying.

Best binned chips go to titan X.
980ti getting the rest, and some of these chips require higher voltage. In one review I saw a sample running at 270-280 watts tdp, 30 watts more than TitanX. It's rare but could happen, and such card could be a no go for macpro.

Must mean the Titan X is right at the edge of Mac internal power limits. It does worry me a little but I haven't been able to get it to shut off, even with FurMark. That wouldn't cause any slow/long-term damage to the logic board traces, would it?
 

benjaprud

macrumors member
Apr 9, 2015
92
24
I think the safety mechanism that shuts down the PSU at high power loads is there to prevent any damage to the logic board traces. I'm not certain about this but I guess it should trigger above 300W which is the global power limit of the PCIe slots and power outlets. I've never had any problem so far running an overclocked Titan X at constant 110% TDP. The only drawback is that the PCI and PSU fan speeds are linked to power consumption and get very noisy at 275W. This incited me to do the internal PSU mod anyway (solder an 8 pin PCIe cable directly into the PSU to the GPU) which resulted into much more acceptable fan speeds without any worrying impact on temperatures (PSU/PCI 925/1550rpm vs 1500/2250rpm at 275W).

I was worried the PSU couldn't handle the Titan X as it has the same TDP than the 780Ti which is notorious for being able to shut down the PSU. I just don't get the exact reason why one would work and not the other. This might be related to the GPU peak consumption and/or slight discrepancy between power safety threshold on different Mac Pros.

As netkas said, the 980ti is a more risky choice as some samples have turned out to be more power hungry, however I've been surprised to see what my MP could handle. I'm also surprised to see that some samples are able to exceed the TDP as it seems that Maxwell cards tend to throttle to strictly enforce the TDP limit. Those who want to give it a go should be prepared to do one of the internal/external PSU mods or to resell the card just in case.
 

h9826790

macrumors P6
Apr 3, 2014
16,619
8,552
Hong Kong
If your PCIe slots 2 and 3 still free, you may install the Titan X in slots 2. AFAIK, this should reduce the fan noise.
 
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s.m.t.

macrumors 6502
Mar 7, 2010
285
22
I think the safety mechanism that shuts down the PSU at high power loads is there to prevent any damage to the logic board traces. I'm not certain about this but I guess it should trigger above 300W which is the global power limit of the PCIe slots and power outlets. I've never had any problem so far running an overclocked Titan X at constant 110% TDP. The only drawback is that the PCI and PSU fan speeds are linked to power consumption and get very noisy at 275W. This incited me to do the internal PSU mod anyway (solder an 8 pin PCIe cable directly into the PSU to the GPU) which resulted into much more acceptable fan speeds without any worrying impact on temperatures (PSU/PCI 925/1550rpm vs 1500/2250rpm at 275W).

I was worried the PSU couldn't handle the Titan X as it has the same TDP than the 780Ti which is notorious for being able to shut down the PSU. I just don't get the exact reason why one would work and not the other. This might be related to the GPU peak consumption and/or slight discrepancy between power safety threshold on different Mac Pros.

As netkas said, the 980ti is a more risky choice as some samples have turned out to be more power hungry, however I've been surprised to see what my MP could handle. I'm also surprised to see that some samples are able to exceed the TDP as it seems that Maxwell cards tend to throttle to strictly enforce the TDP limit. Those who want to give it a go should be prepared to do one of the internal/external PSU mods or to resell the card just in case.
Do you have a link to how to add the 8 pin connection to the PSU?
 

benjaprud

macrumors member
Apr 9, 2015
92
24
Well I found enough information in these two threads to get me started :

https://forums.macrumors.com/threads/titan-x-best-mac-pro-card.1852113/
https://forums.macrumors.com/threads/pixlas-4-1-mac-pro-mod.1859652/

I also translated the essential information and reported my experience on a french forum here :

http://forum.macbidouille.com/index.php?showtopic=388917

There is no precise tutorial. The mod requires a bit of disassembling and soldering skills, don't do it if you can't solder properly or are afraid to disassemble a PSU (or alternatively try the solderless mod from the second link). If you feel confident enough with the required knowledge and skills then these links should be enough. If not you should find someone to help you do it (electrician, electronics technician, DIY hobbyist).

The mod is for 4.1/5.1 Mac Pros. There's nothing too complicated there, you have to spot the +12V and GND terminals into the PSU, solder the 8 wires of a PCIe cable to them and route the cable to the GPU. Each one of those who completed the mod took his own approach to it. I used two PCIe 8 pin 45cm extender cables, one hooked to the GPU, cut one end of the other to solder it on the PSU and connected the two together.
 
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s.m.t.

macrumors 6502
Mar 7, 2010
285
22
Thanks, exactly what I was looking for. Wanted to see what was involved before tearing into the PSU. I can solder and not worried about doing some custom electrical work, as I have done a fair bit of that when I was modding PCs. Also want to be able to return it to stock if need be, so I don't want to do any permanent alterations like drilling holes. Cables can be unsoldered if need be or maybe even put connectors in.
 

s.m.t.

macrumors 6502
Mar 7, 2010
285
22
how many devices are you powering? I have 4 spinning drives, 1 SSD, and 1 optical drive... Even putting in a power feed straight from the PSU, would be concerned about overloading the PSU...

Edit: I see the label lists the PSU as having 980W of total output, but would be good to know if anyone else has as many drives...
 
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s.m.t.

macrumors 6502
Mar 7, 2010
285
22
Got mine in yesterday, powering the 8-pin off a 12v line soldered straight to the PSU. My idle amperage actually is lower than with the 660Ti, the clip I took of the loads using iStat was obviously just one point in time and may not have been representative of the normal load though. The difference was about 2A less on the 12v rail.

This card is really fast!!

Now I am wondering if there is a EFI flash for these cards.
 
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s.m.t.

macrumors 6502
Mar 7, 2010
285
22
Bit of a bummer:
http://forum.netkas.org/index.php/topic,11150.0.html

Hard to justify the cost of having it done just to see a boot screen. That and didn't want to have to ship out my card.

Maybe when I am ready to add one for SLI in Windows I will buy one from them...

Edit: Anyone else with a 980Ti have it reported as just NVIDIA Graphics Device in about this mac?

With the 660Ti:______________With the 980Ti:
Sensors%20Idle%20660Ti_zpsdlmotkns.png
Sensors%20Idle%20980Ti_zpsrj4tzvca.png
 
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xactoman

macrumors member
Jul 9, 2015
45
10
I just got a GTX 980 Ti and I have to say I am having some trouble. I installed it, boots off the web driver, but it is far from smooth. Mouse is jittery, floaty and sometimes like pushing mud. GPU programs like creative cloud eventually bog down. It's very hard to use in the yosemite interface. Put the GTX 680 back in and it's all normal.

Can't figure it out. 980 reports excellent render times in Blender and Cuda-z, but it doesn't seem to be working to it's full potential on the Mac UI. Thought it was maybe drivers, but then saw that others were using it just fine. It reports in system profiler as "nvidia graphic device" and in photoshop shows up as experimental nvidia...not sure what I should do. I would really like to use this card. Could it be it's not getting enough power?
 

Upgrader

macrumors 6502
Nov 23, 2014
353
53
not good news, sorry to hear it. Did you upgrade the driver before you installed the Ti? Have you reseated the card?
 
Jul 4, 2015
4,487
2,551
Paris
I don't like the Ti, Titan X or Fury. I feel they are stuck somewhere between the 1080p gamer cards and the true 4K gaming cards that are still more than a year away. I wouldn't spend so much money on a kind of in-between generation.
 
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