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SolidCake

macrumors regular
Original poster
May 20, 2016
109
41
Hey guys, I'm thinking about switching out my dual RX 480's for a single GTX 1080 Ti. The lack of Apple support on AMD's front (vice versa) and the newly acquainted support from Nvidia is making me seriously consider a switch.

I was wondering if anybody has a 1080 Ti running in their Mac Pro? How is performance? And how did you manage the power requirements? Do you need to flash the card or can you use Nvidia's latest web driver for macOs?

Cheers!
 

flowrider

macrumors 604
Nov 23, 2012
7,317
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Last edited:

SolidCake

macrumors regular
Original poster
May 20, 2016
109
41
Thanks for the information, Lou! By the looks of it it would work fine. What would you recommend for power distribution from the Mac Pro to the 250W 2x8 pin card?
 

h9826790

macrumors P6
Apr 3, 2014
16,656
8,584
Hong Kong
I don't have the 1080Ti. However, you can browse through the first few pages of this forum, then you will have some idea about how the Pascal card doing on cMP now (mainly how the web driver perform). e.g.

https://forums.macrumors.com/thread...-glitchy-after-wake-up.2044750/#post-24559221

https://forums.macrumors.com/threads/color-shift-in-google-chrome-w-gtx-1080.2044879/#post-24562357

https://forums.macrumors.com/thread...ring-after-4-days-good.2043717/#post-24555097

https://forums.macrumors.com/threads/webdriver-for-gtx-1080-1070.1979778/page-16

https://forums.macrumors.com/threads/pascal-opencl-performance-issues.2042745/#post-24518036

And I leave you to decide if that's good performance. If require, you may ask some 1080Ti user here to perform some standard test. And then compare the result to your dual RX480. They are usually very helpful. However, you have to clearly state what and how exact the test to carry out. Otherwise, the result can be quite meaningless.

For power management. There is a little device call EVGA PowerLink. With this little device, your Mac should able to power the 1080Ti without any issue. It is possible to power the card by just using the mini 6 -> 8pin cable. However, that not necessary always work. A bridge in between to make sure the mini 6pins can share the load is a much much better way to do it. Of course, you can also tailor made a cable that can share the load. Or simply use a single 8pin in the middle as the bridge. Or even go through the Pixlas mod. There are lots of method to power the 1080Ti. But I must emphasis that, NONE of the method is guarantee. ALL of them are some kind of mod, or allow the card to draw more than the mini 6pin's official limit. But in real world experience, it's not a problem at all (if you do it correctly).

And NO, you don't need to flash he card. flash card can provide boot screen, but not a requirement to make it work on cMP.

YES, you can use the latest web driver (that means you need the latest MacOS as well). In fact, you MUST use the latest web driver. Without the driver, the card is just a piece of brick inside the cMP. Since you know how to make the RX480 work, so I assume install and active the Nvidia web driver is a simple job for you.
 

flowrider

macrumors 604
Nov 23, 2012
7,317
2,998
Thanks for the information, Lou! By the looks of it it would work fine. What would you recommend for power distribution from the Mac Pro to the 250W 2x8 pin card?

Contact MVC and see how they are running theirs.

I am running a Gigabyte GTX 1080 Gaming G1 so I don't have that issue. One 8 pint connector is all I need.

And no, you don't need a flashed card, but there are things we do during boot that we would lose without a boot screen.

Lou
 
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Gazember

macrumors member
Apr 5, 2017
51
19
I had a 1080 Ti but returned it and I'm considering two RX 480s (already have one).

I have been following your posts and what you learned from using the 1080 Ti and decided to get the RX 580. It works great with FCPX and Resolve. If I need boot screen I can always swap back my flashed HD 7950.

It seems that Nvidia GPUs work great for gamers while video application users are better off with AMD GPUs, perhaps with the exception of Premiere (that I don't use).

I wonder how the OP uses his MP primarily.
 

flowrider

macrumors 604
Nov 23, 2012
7,317
2,998
^^^^Over the years I've sometimes had trouble with Bare Feats and Safari. I've reported it to Rob, and he does not know what the issue is. When I have an issue, Firefox always opens up and offending (with Safari) web site.

The link posted by mattspace works fine in Firefox.

Lou
 

mattspace

macrumors 68040
Jun 5, 2013
3,329
2,965
Australia
The link posted by mattspace works fine in Firefox.

The link wasn't originally there. I figured anyone on this forum would be fine to just go to the barefeats website, look the list of articles, see May 12th, 2017 -- Mac Pascal NVIDIA GPU Shootout (TITAN Xp, 1080 Ti, 1080, 1070), and read it.
 

AndreeOnline

macrumors 6502a
Aug 15, 2014
704
495
Zürich
I have been following your posts and what you learned from using the 1080 Ti and decided to get the RX 580. It works great with FCPX and Resolve.

I think the RX 580 is a great card to put in a Mac Pro, if you're OK with the kext mods. It's around half the performance of a 1080 Ti, but less than half the price. Also, it's a card where your Mac can utilise all of the card's potential across the board with no reservations.

The 1080 Ti is a powerful racehorse that you pay a lot for to use. In the scenarios where it can stretch its legs (my DaVinci Resolve tests and certain Maxwell Render use cases) you get all of your money's worth. But then there are many cases where you don't see its full potential. There are also some instabilities—some people might be fine with these, but for me they were a show stopper.

Even not considering the show stopping side of things, since there are some issues where you don't see full performance, that makes the price/performance aspect less attractive.

If you need/want equal performance to a 1080 Ti, you could run two RX 580's for less money. Apps need to be multi GPU aware, which FCPX, Motion and Resolve are. I don't use PPro (and only little AE), so I'm not speaking to that.

It seems that Nvidia GPUs work great for gamers while video application users are better off with AMD GPUs, perhaps with the exception of Premiere (that I don't use).

This isn't quite in line with what I've said. I DO think it's a strong gaming card if you get full acceleration. But I didn't with F1 2016 (RX480 was stronger) and the 1080 Ti hung the computer. In X-Plane I'm CPU limited. with my two 3.46GHz Xeons.

DaVinci Resolve is a really attractive choice for editing/color/sound right now. The full Studio version is only $299, plus there is an almost complete free version you can simply download. The 1080 Ti is a perfect card for Resolve on the Mac. In fact, if editing and color was all I did, I'd easily keep the card and be happy! Strong recommendation!
[doublepost=1494751199][/doublepost]
Barefeats has recently published a big comparison of the various Pascal cards, and multi-card setups in the cMP. Makes for some interesting reading.

Barefeats is a great site*. If you follow it, you'll have nice factual information almost as quickly as if you read Macrumors Mac Pro forum.... =)

My reservations to his latests tests with so much compute power is that he should move up from 1NR node to the 6NR node test. His 60 fps score with dual 1080 Ti is limited by things other than the cards. With tougher tests (available in the benchmark) you'd see the same linear increase (double performance) maintained with the two 1080 Ti's all the way.


*= No irony. It's a great site!
 
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SolidCake

macrumors regular
Original poster
May 20, 2016
109
41
Hey, thanks for all the great comments!

I’ll go over my reasons as of why I am considering the switch and I’ll do my best to reply to all of your comments in this post.

I use my cMP mainly for work (Design & Web development) and some gaming via a Windows 10 SSD. Drive bay 1 has the latest macOS (SSD), drive bay 2 has Windows 10 (SSD) and drive bay 3 and 4 are two 3.5” drives for project data management.

I bought a pair of XFX RX480’s 8GB (OC) in the hope that they would get some official support and because they require just one 6 pin connector each. This would make it an ‘easy’ fit for my 2009 cMP. I really like the performance of these cards and ‘bang for buck’ that they have but I’m getting fed up with the lack of support, both from Apple and Windows. Here’s a list of my pro’s and cons.

Pros:
  • High value bang for buck
  • Very stable after kext edit in macOs
  • Just one 6 pin connector each

Cons:
  • No macOs UI scaling, makes displays with 1440p and above almost unreadable.
  • Kext edit with every macOs update
  • Loud under heavy load
  • Atrocious AMD Crossfire support on Windows

Lou, h9826790 thanks for all the great info!

the 1080 Ti hung the computer
How did you power the GTX 1080 Ti?

How would one properly power a 250 watt card that has two 8 pin connectors without modding? Can you use the sata cable from the optical bay?
 

ventricle

macrumors regular
Nov 28, 2016
110
160
Oz
I thought about that a lot, until I realized it would be like gifting a 75-year-old with Olympic class sprinter shoes. In other words, yeah, no more GPU-limited experience; it would be CPU-limited. At the moment things are in reasonable balance with an HD 7950 and 2x3.33 6-core Xeons.
 

AndreeOnline

macrumors 6502a
Aug 15, 2014
704
495
Zürich
I thought about that a lot, until I realized it would be like gifting a 75-year-old with Olympic class sprinter shoes.

If you know what you're doing, to use your example, it's more like the 75 year old is hiring the fastest sprinter out there to run in his place.

Notice the caveat: you need to know when the sprinter is available and when he's off endorsing soft drinks making you run the race yourself on your tired ass 75 year old legs—even if you've got 12 of them....

Barefeats tests are accurate and show you get full use of the GPU, even two of them, under the right circumstances. But the apps Barefeats use are handpicked to show that. It's not random "pro apps". His 3D apps use GPU and Resolve does too.

In a line towards the end he says you won't see the same benefit in FCPX or PPro "because they are CPU limited". I don't agree with that simplification, but you don't get the same boost in those apps.
 

ventricle

macrumors regular
Nov 28, 2016
110
160
Oz
Depends on the application that drives your needs; I need both GPU and CPU power, and I’m better off with spending on a different solution rather than giving the old workhorse half a boost.
 

iCreate

macrumors member
Sep 2, 2002
99
11
Near Insanity
Hey guys, I'm thinking about switching out my dual RX 480's for a single GTX 1080 Ti. The lack of Apple support on AMD's front (vice versa) and the newly acquainted support from Nvidia is making me seriously consider a switch.

I was wondering if anybody has a 1080 Ti running in their Mac Pro? How is performance? And how did you manage the power requirements? Do you need to flash the card or can you use Nvidia's latest web driver for macOs?

Cheers!

It's running fine on my 2009 cMP. I have it powered by a dual mini 6 pin to 8 pin and a dual SATA power to 6 pin. No issues so far. May get it flashed, but right now I just have a GT120 in it. I read somewhere that to get PCI2.0 speeds you must get it flashed, but I'm not so sure about that. I have to look into it.
 

SolidCake

macrumors regular
Original poster
May 20, 2016
109
41
It's running fine on my 2009 cMP. I have it powered by a dual mini 6 pin to 8 pin and a dual SATA power to 6 pin. No issues so far. May get it flashed, but right now I just have a GT120 in it. I read somewhere that to get PCI2.0 speeds you must get it flashed, but I'm not so sure about that. I have to look into it.
Did you get UI Scaling in macOs? Have you also tried the card with Windows 10? How is the noise? I do a lot of web development and I really miss UI Scaling on a 1440p monitor with the RX 480's. I do some light gaming on Windows 10 and you can forget about any 'real' Crossfire support. Most of the games are unplayable in Crossfire.
 

iCreate

macrumors member
Sep 2, 2002
99
11
Near Insanity
Yes, 3440x1440 native with multiple scaling options. It's pretty quiet even when running benchmarks. No power issues, no display glitches. I haven't installed Windows on it so I can't be sure how it will be under load running any games.
 

SolidCake

macrumors regular
Original poster
May 20, 2016
109
41
Thanks, that sounds good! One last question, might the CPU or RAM be a bottleneck for the card?
 

h9826790

macrumors P6
Apr 3, 2014
16,656
8,584
Hong Kong
Thanks, that sounds good! One last question, might the CPU or RAM be a bottleneck for the card?

I think this has been discussed many many time. And the answer is "depends". It very depends on how you use it.

e.g. For gaming. The same game can be CPU limiting in 1080P normal setting, but GPU limiting in 4K max setting (even though you use 1440P monitor, you can still render at 4K with super resolution).
 

SolidCake

macrumors regular
Original poster
May 20, 2016
109
41
Thanks for clearing that up! I just ordered a MSI GTX 1080 Ti Founders Edition. Once I have it installed and have ran some tests I'll get back to you guys with my so far opinion.
 

HHarm

macrumors regular
Mar 4, 2009
138
2
a few questions.....
- 1080Ti only works in Sierra?
- Anybody know if the latest Sierra versions corrected the bug were the mouse pointer doesn't update properly on a 5K display? I had to rollback to El Capitano from 10.12.2 because of the problem.
 
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