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Fusion Bassist

macrumors newbie
Original poster
Apr 9, 2009
3
0
It seems that with this technology and with Snow Leopard coming out that this should be a no brainer. However, the recent refresh has shown little signs of picking this up. The Mac Pro has had multi gpu options for a while so nothing new there, but the iMac didn't get anything in the way of multi GPUs. So with the Mac Pro and the MBPro having multi GPUs, it may just be that their saving it for their pro line.

Since Snow Leopard is supposed to bring about OpenCL which will use the GPU, why have we heard nothing about SLI or Crossfire? These would greatly benefit the system. It seems to me that Apple could benefit greatly from using this technology, not just for the OS, but for a better hardware position. Thoughts?
 

MacVidCards

Suspended
Nov 17, 2008
6,096
1,056
Hollywood, CA
I agree it would seem like a no-brainer.

Yet Apple is dragging their feet on this, much like their Blu-Ray support.

It might make a nice combo when Snow Leopard comes out though....
 

Boneoh

macrumors 6502
Feb 27, 2009
318
2
So. Cal.
I'm not sure what SLI and crossfire offer vs. OpenCL. Seems to me that OpenCL is much more software oriented at the application level and somewhat device independent. I mean this in the sense of the amount of cores and memory are still limiting factors, but the use of OpenCL on any supported cards would still be the same as far as the application programming.

Are SLI and Crossfire more tightly coupled together at the hardware level? I'm not sure if I am asking this correctly, but in order to use SLI and Crossfire is the hardware compatibility between the GPUs the key to success?
 

soldierblue

macrumors 6502
Mar 23, 2009
324
5
I'm not sure what SLI and crossfire offer vs. OpenCL.

They're not really comparable. OpenCL is the execution of code across multiple processor types (including GPUs), but SLI/Crossfire are just a means to get multiple GPUs to work together from a rendering perspective. Alternate-frame rendering and such.
 

Boneoh

macrumors 6502
Feb 27, 2009
318
2
So. Cal.
They're not really comparable. OpenCL is the execution of code across multiple processor types (including GPUs), but SLI/Crossfire are just a means to get multiple GPUs to work together from a rendering perspective. Alternate-frame rendering and such.

Ahhh! The light bulb just went on :) It's directed towards the graphics side, vs. OpenCL towards the pure mathematics. Thanks!
 

Umbongo

macrumors 601
Sep 14, 2006
4,934
55
England
Apple's history towards graphics card hardware and drivers should tell you all there is to know really. I really doubt you will see this anytime soon.
 

Tallest Skil

macrumors P6
Aug 13, 2006
16,044
4
1 Geostationary Tower Plaza
It's difficult for Apple to justify supporting two concepts designed for gaming... when they don't have GAMES.

Oh, and when only one computer would be able to truly take advantage of this, and that one computer cannot physically support either technology as shipped by Apple, and that one computer is not sold to an audience that would give a crap. :p
 

Tesselator

macrumors 601
Jan 9, 2008
4,601
6
Japan
SLI and Crossfire are NOT just for gaming. I haven't ever used either but my colleges tell me it assists any Open GL display. That's most CG applications, things like Apple Motion, and now stuff like Photoshop too.

But to answer the question of whether or not Apple will support it... I would say no! They know the benefits and it's already been 5 years. They haven't yet so I guess they never will. Why? Speculation but maybe their engineering stuff just isn't good enough! (wolf ticket!)
 

Fusion Bassist

macrumors newbie
Original poster
Apr 9, 2009
3
0
It's difficult for Apple to justify supporting two concepts designed for gaming... when they don't have GAMES.

Oh, and when only one computer would be able to truly take advantage of this, and that one computer cannot physically support either technology as shipped by Apple, and that one computer is not sold to an audience that would give a crap. :p

But with OpenCL GPus aren't just for games. They're talking about the "vast gigaflops in the underused GPU" that will become available from OpenCL, having more GPUs will only increase the performance from OpenCL. They can't really claim it as a gaming tech with this, not to mention other professionals who would benefit from having more GPU power like 3D designers, artists and what not. It could also serve as a step to leveling the playing field in mac vs windows arguments about hardware. It seems to me that Apple isn't looking at this correctly.
 

cmaier

Suspended
Jul 25, 2007
25,405
33,471
California
But with OpenCL GPus aren't just for games. They're talking about the "vast gigaflops in the underused GPU" that will become available from OpenCL, having more GPUs will only increase the performance from OpenCL. They can't really claim it as a gaming tech with this, not to mention other professionals who would benefit from having more GPU power like 3D designers, artists and what not. It could also serve as a step to leveling the playing field in mac vs windows arguments about hardware. It seems to me that Apple isn't looking at this correctly.

But Apple supports multiple GPUs, and I'm sure the multiple GPU's will work with OpenCL. Multiple GPUs != crossfire/SLI.
 

nanofrog

macrumors G4
May 6, 2008
11,719
3
But Apple supports multiple GPUs, and I'm sure the multiple GPU's will work with OpenCL. Multiple GPUs != crossfire/SLI.
As I understand it (from t0mat0's thread), it will support mulitple GPU's. For the second part, you beat me to it. :D :p
 

VirtualRain

macrumors 603
Aug 1, 2008
6,304
118
Vancouver, BC
It's difficult for Apple to justify supporting two concepts designed for gaming... when they don't have GAMES.

Oh, and when only one computer would be able to truly take advantage of this, and that one computer cannot physically support either technology as shipped by Apple, and that one computer is not sold to an audience that would give a crap. :p

This is absolutely true...

For either solution to work properly (render frames correctly) they need driver profiles for EACH game.
For either solution to offer any value, you need to have two identical cards that when combined offer more power than a better single card solution.

Think about this last sentence... what two cards can you combine, and in what system, that when paired together, offer more power than an available single card solution? NONE!

The only system that can possibly support this, is of course the Mac Pro. The only cards you can combine in that system are two GT120's. Even 4 GT120's in QUAD SLI won't outperform a SINGLE 4870. The Mac Pro can't support dual 4870's (lacking power connections).

This is just a couple of good reasons why Apple, Nvidia, or ATI won't be supporting either of these solutions any time soon. Keep in mind it's not just an Apple decision... Graphics card manufacturers would have to be motivated to provide capable drivers and/or license it. The market for this technology is probably .0001% of the total GPU market... do you think they care about a market that size?

Perhaps the most compelling clue is the ridiculously minimal choice we have for graphics cards... Apple, Nvidia, and ATI simply don't take the MP market seriously for high-end graphics... if they did, we would see higher-end cards more often for this platform. Apple most likely has to PAY Nvidia and ATI to build cards for the Mac Pro. If they didn't have to pay and both companies saw this as a lucrative market for them then every card both companies offered would be available in a Mac Pro version. ATI and Nvidia have much bigger markets to worry about than ours.

One last comment... be careful what you wish for. One of the appeals of OSX and Apple computers is their rock-solid stability. Vista was largely such a flop early on because of terribly poor driver support (particularly from Nvidia and ATI) despite the OS being in beta for nearly a year! SLI and Crossfire are also both flaky as hell and most people that have used either will never do so again. Do you really want this on OSX?
 

Saladinos

macrumors 68000
Feb 26, 2008
1,845
4
SLI and Crossfire are proprietary hack jobs limited to a niche market. It's not going to help Apple's growth, but it will add code that needs to be maintained and clutter up the platform.

Besides, once Larrabee comes along, we won't need either of them ;)
 

VirtualRain

macrumors 603
Aug 1, 2008
6,304
118
Vancouver, BC
SLI and Crossfire are proprietary hack jobs limited to a niche market. It's not going to help Apple's growth, but it will add code that needs to be maintained and clutter up the platform.

Besides, once Larrabee comes along, we won't need either of them ;)

LOL... yeah... what he said! BTW, you said in 2 sentences what I needed nearly two pages to say! ;)
 
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