15 replies to this topic

[ikir]

Hi all, i got a very big luck to get a Mac Pro late 2013 (D500s) for a very low price, selling my super Mac mini and MacBook Pro 13" retina i got it for nothing! But this is another story.

Working with it it is a dream, video making, using Pixelmator... all super fast....

Games also runs super smooth with all detail to max, Borderlands 2, Tomb Raider, Diablo 3... anyway i'm curious if Feral and Aspyr are working on supporting dual GPUs on their games, even a basic support with OpenCL. I've read months ago there was a games using Dual GPUs for supporting higher res on Mac pro. This could be a speed boost also on many MacBook Pro 15" and iMac.

Still hoping to see Metal or Mantle coming to OS X.

PS: it seems that Yosemite 10.10 have much more faster OpenGL for many recent and not so recent Macs. Many Mac gamers report 10-20 more fps in games with public beta 1.

[Thain Esh Kelch]

Metal would not make sense on OSX.

[Sneaky Snake]

You are able to crossfire the GPU's in Windows, but as far as I know there is no dual GPU support in OS X for any games.

[ikir]

You can use dual GPU in games in OS X but the game needs to be coded with that support. Or you can use second GPU as OpenCL core for physics but still the game must support it. Would be awesome to know Aspyr and Feral plans for dual GPUs

[Tetsuya]

Given the amount of the market that could take advantage of it (the tiny fraction of Mac users who have a Mac Pro), it simoly wouldnt be worth their time to bother, honestly.

[Sneaky Snake]

ikir, on 12 August 2014 - 03:23 AM, said:

You can use dual GPU in games in OS X but the game needs to be coded with that support. Or you can use second GPU as OpenCL core for physics but still the game must support it. Would be awesome to know Aspyr and Feral plans for dual GPUs

There's probably less then a thousand people (pulling number out of my ass) who have 1 - a mac, 2 - dual GPU's, and 3 - care about gaming enough to want dual GPU support. There simply not the market share for it. Even on the PC side of things, people with dual GPU's is a tiny fraction of those with single GPU's.

It would be awesome if they added support, but I think it's about as likely as seeing a mid range Mac tower with customizable CPU, GPU, etc.

[macdude22]

Sneaky Snake, on 12 August 2014 - 01:32 PM, said:

There's probably less then a thousand people (pulling number out of my ass) who have 1 - a mac, 2 - dual GPU's, and 3 - care about gaming enough to want dual GPU support. There simply not the market share for it. Even on the PC side of things, people with dual GPU's is a tiny fraction of those with single GPU's.

It would be awesome if they added support, but I think it's about as likely as seeing a mid range Mac tower with customizable CPU, GPU, etc.

If my radeon 5970 was any measure, that popsnizzle barely worked right on Windows. Just what I want Mac porting houses to dedicate their limited resources to. Microstuttering, constantly having to dick with catalyst settings, this game won't work at all unless you get some hacked crossfire updates. And this was a damn card that it was all supposed to be built in. I think its gotten better but I got a good deal on a GTX480 and put that in the PC a few years ago.  Then I got the 680 for the Mac Pro and I rarely even go to the basement to boot the PC anymore. I should have bought a motorcycle and not a 5970.......

[Frost]

Tetsuya, on 12 August 2014 - 12:30 PM, said:

Given the amount of the market that could take advantage of it (the tiny fraction of Mac users who have a Mac Pro), it simoly wouldnt be worth their time to bother, honestly.

Given how little attention multi-GPU users get on the Windows side and they're an order of magnitude larger than the pool of 2013 Mac Pro gamers, I can definitely see this being the case.

[ikir]

Not just Mac Pro but many Macbook Pros and iMacs have 2 GPUs

[macdude22]

ikir, on 13 August 2014 - 12:16 PM, said:

Not just Mac Pro but many Macbook Pros and iMacs have 2 GPUs

There would be little value in attempting to use the drastically different architectures of the 4000HD and 650M in my Macbook to any meaningful performance boost. In those macs the slower video is there mostly because it's a function of the chipsets apple is using, and switching to it can generate some power savings. My understanding with most Dual GPU solutions, and the reason they have to be very similar in architecture, is each gpu will generate a frame and then they are merged somehow at the output. I think some SLI/Crossfire builds may have rendered half or quarter frames and put it together for output. There wouldn't be a benefit to having the 4000 in my MBP render any frames vs the 650 in a game.

These devices have 2 GPUs but not Dual GPUs if we want to use that as a differentiator.

[Smoke_Tetsu]

That's always been the idea of SLI going back to the 3Dfx days. Two identical GPUs rendering the game thus giving double the performance or double the resolution at the same performance. Not one GPU rendering at max and one completely different one pulling up the rear.

[Aspyr-Blair]

Well, this is actually a pretty complicated subject...but you guys are fairly dead on with assumptions.  The user base is just too small.

We messed around with it when we added 4K support to Civ V, but then we shifted our focus to OpenCL to reach a MUCH MUCH broader user base with the update.

So yeah...unless us or Feral have a glut of bandwidth (not likely given what both of us are working on), this probably wont happen any time soon.

[edddeduck]

I have posted on a few topics like this before but just to give a few thoughts again...

Dual GPU support is tricky as no CrossFire support exists on OS X. This means you cannot enable it easily in games like you do on Windows.

In theory you could write all the code yourself and work out how to push frames between the two cards etc by DMA'ing the memory (I believe something like this exists on the Pro as I suspect FinalCutPro does something similar when working on 4K videos) but it would be a massively complex task especially for a game which is a lot more complex than a simple frame by frame render. Even on Windows SLI in games can be unreliable on certain games or drivers.

I am not saying it isn't impossible, it is definitely a nice idea however given the work required you have to look at other tasks that would be delayed or cancelled if you take the time to do something like this as you don't have infinite resources. When making decisions you also look at features that will benefit all gamers in much more impressive ways like supporting DX10 and DX11 advanced features using OpenGL4 and OpenCL.

In this case we thought about SLI long before the new MacPro's we have in fact looked at this since the PowerMac G4 4xAGP days (2000?) and a few times since but each time the complexities and limited number of users who would benefit lowered the importance of this feature as supporting newer graphics features, force feedback, DX9, DX10, Native Intel support & performance to name a few features were deemed more important to work on first.

Right now we are in the early days of GL4 on the Mac and we have more and more games that need the latest DX10 and 11 features to even draw as the older graphics modes are no longer being used. This is great for gamers but it also means all game companies working on the Mac have a lot of work to get these impressive effects working optimally. New features in an OS always take time to take the best advantage of and also to work with Apple and the graphics companies to improve performance and fix any rendering issues. Right now that is a greater priority than potential SLI features.

That's not to say it won't happen just right now there are bigger tasks with greater potential gains for all users that will likely be worked on first.

Aspyr-Blair, on 13 August 2014 - 02:36 PM, said:

So yeah...unless us or Feral have a glut of bandwidth (not likely given what both of us are working on), this probably wont happen any time soon.

It's 21:40PM over here in the UK so I can safely agree with Blair that we have a lot of awesome stuff in the pipeline (and I am sure Aspyr do too) but awesome stuff takes time and effort meaning SLI is not at the top of the queue right now. Good night all, I think I need some "me" time before bed... Selfish I know

[ikir]

Thanks to both edddeduck and Blair, it is always incredible to see companies writing on comunity forums, it is a great thing, thanks!!!

Ok so me can hope to see OpenCL support in more games, it would be a great start!
Maybe Apple will introduce something in the next SDK to take advantage of Dual GPUs, many things were tricky on other reality get simpler with XCode... At least we can hope.

[Smoke_Tetsu]

It'd be great if that OpenCL support was used for hardware accelerated physics. That's one thing I've been pining for in my games besides having full multichannel surround sound support standardized (and perhaps extended to support stuff like AC3/DTS encoding).

[edddeduck]

Smoke_Tetsu, on 14 August 2014 - 07:41 AM, said:

It'd be great if that OpenCL support was used for hardware accelerated physics. That's one thing I've been pining for in my games besides having full multichannel surround sound support standardized (and perhaps extended to support stuff like AC3/DTS encoding).

That would require vendor support most likely. Would be nice but unlikely something a game company would do more a middleware vendor. Like Nvidia have done with PhysX for example on Windows.