Did you know your 2013 Mac Pro
has built-in CrossFire?

Posted Thursday, January 23rd, 2014 by rob-ART morgan, mad scientist

Did you know that if you boot Windows on your 2013 Mac Pro, you can run the dual GPUs in CrossFire mode? The OWC Lab ran some tests for us on a two new Mac Pros running Windows 8.1. For perspective and encourgement to legacy Mac Tower owners, we included results for a matching pair of AMD GPUs in our 2010 Mac Pro tower.

GRAPH LEGEND
nMP 6c D500*2 = 2013 Mac Pro 6-core with dual FirePro D500s 'CrossFired'
nMP 4c D300*2 = 2013 Mac Pro 4-core with dual FirePro D300s 'CrossFired'
MP 6c R9 270*2 = 2010 Mac Pro 6-core with dual ASUS R9 270s 'CrossFired'

nMP 6c D500*1 = 2013 Mac Pro 6-core with dual FirePro D500s 'UN-CrossFired'
nMP 4c D300*1 = 2013 Mac Pro 4-core with dual FirePro D300s 'UN-CrossFired'
MP 6c R9 270*1 = 2010 Mac Pro 6-core with dual ASUS R9 270s 'UN-CrossFired'

Diablo III -- 'Evil is in its prime.'
Our lonely traveler is on the path to adventure stopping occasionally to zap the undead. Settings are 2560x1440 Fullscreen, vSync OFF, High Quality, Anti Aliasing enabled. (LONGER bar indicates FASTEST in frames per second.)

World of Warcraft: Mists of Pandaria
'Narache Village Run' at 2560x1440, Ultra preset, 1X MSAA, Vsync Disabled. (LONGER bar indicates FASTER in Frames per Second.)

INSIGHTS
It should be clear from the graphs above that if you are a hard core gamer running Windows in your 2013 Mac Pro's Boot Camp partition, you can use the CrossFire mode to 'fuse' the dual FirePro GPUs so the game treats them as one really fast GPU.

The AMD FirePro pair that ships in each 2013 Mac Pro is already physically CrossFired. On the other hand, the AMD GPUs in the Mac Pro towers require the CrossFire cable connecting the matching pair. The Windows AMD Catalyst Manager lets to enable and disable CrossFire mode without having to reboot.

We chose a pair of AMD R9 270s for our tower experiment. They don't run under OS X -- yet -- but they were certainly 'pumped up' with CrossFire enabled.

Not all Windows apps benefit from CrossFire mode. We 'cherry picked' the two above to make our point. Also, in case you don't know it, CrossFire mode is not supported by OS X -- yet.

If you prefer to run your games under OS X, that's cool. But just be aware that only one GPU will be active -- unless the game developers decide to add the code to enable both of them.

As for legacy Mac Pro tower owners, if you have matching NVIDIA GPU, they don't support CrossFire. That's strictly an AMD thing. But they do support Scalable Link Interface (SLI) mode. Yet, the SLI jumper is not recognized on the Mac Pro tower even if you are running Windows. It does not support Virtualization Technology. Never fear. There is a utility called 'HyperSLI' that can enable Software Mode. It's not as good as Hardware Mode but is worth a try to squeeze out more FPS.

Comments? Suggestions? Email , mad scientist.
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WHERE TO BUY NVIDIA GPUs for your MAC PRO tower

• The OS X compatible GeForce GTX Titan can be purchased from MacVidCards. They also offer a flashing and mod service for your existing GTX Titan for $200. MacVidCards recommends a supplemental power supply. We were able to run it in our 2010 Mac Pro without the aide of an auxiliary PS.
• The OS X compatible GeForce GTX 780 is available from MacVidCards. They offer a flashing and mod service your existing GTX 780 for $200.
• The OS X compatible GeForce GTX 770 (2G and 4G) is available from MacVidCards.
• The EVGA GeForce GTX 680 Mac Edition can be ordered from EVGA direct or from Other World Computing (MacSales.com), Trans International (TransIntl.com), NewEgg, and Amazon.
• The GeForce GTX 680 Classified 4G is available* from MacVidCards. (*out of stock as of this writing but watch for more to appear)
• The GeForce GTX 680 4G is available from Mac*Pro.
• The NVIDIA Quadro K5000 for Mac is available from OWC and Amazon.
• The NVIDIA Quadro 4000 for Mac is available from OWC and Apple Store USA.

• The Radeon HD 5770 and 5870 is available from OWC and Apple Store USA.
• The Sapphire Radeon HD 7950 Mac Edition is available from OWC , TransIntl, and Amazon
• A flashed Radeon HD 7970 running at PCIe 2.0 is available from MacVidCards.

WHERE TO BUY AN UP-CLOCKED 12-CORE MAC PRO TOWER

• Visit EditBuilder.com's eBay Store. Or you can email them or call them (1-855-EDIT-BAY). They are offering both tray replacements as well as complete setups with 1-3 year warranties. They also offer up 128GB 1333MHZ RAM and graphics card upgrades for Mac Pro towers.
• Also, check out Other World Computing's Processor Tray Upgrade Program.
• Live in the UK? Visit ScrumpyMacs for 'fire breathing' Mac Pro options.

WHERE TO BUY NEW APPLE PRODUCTS
USA readers can help us earn a commission by using this Apple Store USA link or by clicking on any Apple display ad. For GPUs, click the left side bar option for 'For Mac > Displays & Graphics' to find the GPU kits available. Or if you are buying a new Mac Pro, you can choose GPU options when you configure your order. For UK readers, visit Apple Store UK.

WHERE TO BUY FACTORY REFURBISHED MACS
Apple Store USA has refurbished Macs with 12 month warranty that can be extended to 36 months with AppleCare. Pay attention to the GPU it comes with.

PowerMax not only sells new and used Macs, but will give you a generous trade-in offer on your old Mac.

Other World Computing has a Used Mac Store.

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copyright 2014 Rob Art Morgan
'BARE facts on Macintosh speed FEATS'
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