ATI CROSSFIRE in MAC PRO 2,8 Ghz

Crossfire is well known to work under bootcamp/Windows. OS X though does not support it.

Thank you so much for your information, as I just got 3 2600xt in my Mac Pro 2008 yesterday driving 6 displays for my finance business. Could you help me to set up, questions below:

1. which slot should I connect them to, seems like slot 1 and 2 for both 16x? but I saw they are far away than the slot 2 and 3 close together. Should I connect slot 2&3 instead? I have never seen a crossfire bridge, how far can it extend or it comes in fix lenght? And where to buy it, for how much? Is it comes in different quality by different manufacturers, should I buy direct from ATI?

2. do I have to disconnect my multiple displays and just connect one output in order to play games in crossfire? or just dissable in the driver? do I have to disconnect the crossfire bridge before booting into OSX or it still see my 3 cards correctly?

3. what versions of drivers you are using and where to download it? As I used the original driver come with Mac Pro and 3dmark03,05,06 hanged instantly everytime, dont know why, may be my verions of Windows SP2? what versions of Windows XP are you using?

Hope that I did not ask too many questions, thank you very much for your help in advance. And let's enjoy this "Super Beast" together to the fullest............

Roger Hemstapat

I am planning to buy a $7,000 grand Mac pro 08, I wont if you can not crossfire the cards? did you really make this work ? do you think it is faster than one 8800gt ?
I appreciate you help

There's an even better possibility than CrossFire under Windows using two wimpy Radeon HD 2600 XTs:
If we could convince ATI to release a Mac OS X compatible version of the Radeon HD 3870 X2 (with dual processors on one card).

Yeah! i fully agree. HD3870x2 in Mac Pro would be awesome.

I am planning to see if I can get a single HD3870x2 running in BootCamp.

Me too. But I'm waiting until NewEgg gets the version with the 850MHz cores back in stock.

I got crossfire worked for three weeks now and had been testing all catalyst drivers, my results are below

Windows XP with Catalyst Control Center 8.1,
3DMark03 13755 to 24001(crossfire enabled), 75% increase
3DMark05 10048 to 15005, 49%
3DMark06 4963 to 9231, 86%
Gunmetal Benchmark average frame rate increase 57%.

Windows Vista32 with Catalyst Control Center 7.10,
3DMark03 13190 to 23386, 81%
3DMark05 9689 to 14611, 51%
3DMark06 4775 to 8892, 86%
Gunmetal Benchmark average frame rate increase 77%

Will try CrossfireX driver once available to see whether my 3rd 2600xt scale up in Vista32, will post results, really exciting to see if triple crossfire work in Mac Pro 2008. Thank you very much for all your help and discussion.

Roger Hemstapat

Are you running 3DMark06 with the default settings? And the three default tests (SM2.0, CPU, HDR/SM3.0)?

I have a Radeon HD 3870 X2 that I want to compare to your results.

yes, 3DMark03,05 and 06 are all download demo versions which only allow default settings. Hope 3870x2 will work in MacOSX too, and if anyone here try 8800GT SLI in 2008 Mac Pro yet? Oh, when the new Catalyst 8.3 came out this month, it should support CrossfireX, do you have TWO 3870x2 to test the new QUAD Graphics in Vista(as CrossfireX only works in Vista)? May be I will upgrade my 3 cards to those next year after the price come down. Thank you for your sharing.

Roger Hemstapat

We have a Mac Pro 3.2GHz. We tested five different graphics cards under Windows Vista 64 Ultimate.
3DMark06 overall score at default settings for each:
Radeon HD 2600 XT = 4903
GeForce 8800 GT = 12985
Quadro FX 5600 = 13072
GeForce 8800 GTX OC = 14247
Radeon HD 3870 X2 = 17128

Prey at 1920x1200 High Quality (Shadows Enabled, Image Anisotropy 8X)
Radeon HD 2600 XT = 50 fps
GeForce 8800 GT = 141 fps
Quadro FX 5600 = 145 fps
GeForce 8800 GTX OC = 166 fps
Radeon HD 3870 X2 = 202 fps

CORRECTION (I transposed the GeForce 8800 GT's Prey results with that of the Quadro FX 5600. The following is correct.)

Prey at 1920x1200 High Quality (Shadows Enabled, Image Anisotropy 8X) -- Vista 64 bit
Radeon HD 2600 XT = 50 fps
GeForce 8800 GT = 145 fps
Quadro FX 5600 = 141 fps
GeForce 8800 GTX OC = 166 fps
Radeon HD 3870 X2 = 202 fps

Can anyone confirm or deny that Crossfire works on Vista 64, using Bootcamp drivers on a 2008 Mac Pro?

I need clarification on one point here.
I thought that Crossfire has to be supported by the motherboard. As I recall, the motherboard on the MacPro does not support Crossfire. Therefore, it is not possible to truly run two ATI cards in Crossfire mode. Am I wrong about this?