how many Sapphire Sapphire RADEON R9 270X can i install in my mac pro 2009?

Two-I suppose

BUT, Mr. Postiglione, if you were expecting something like "crossfire" where you can use 2 graphics cards connected together for double the graphics oomph, forget it. Unless you're running something like "Boot Camp", it's not happening. So, you can put two in, and they'll probably work without being flashed-I'm not 100% sure about that, but they ought to..you may not see a boot screen on startup, but once the drivers have loaded, you'll see a picture and it'll work--just no boot screen at all (tough only if you have problems and need to diagnose what's going on)...single card only, alas. I have a sapphire Radeon 7950 which works great in my Mac Pro 3,1, even though I can't run it at 100% full speed (slower PCI-X lanes on older mac pro's and all that...)

hopefully this has answered your question

John B

Probably...

...NONE. It likely draws more power and uses more connections than an unmodified Mac Pro supports.

Provide a link to the exact card you want to install, and Readers can look into it for you.

according to the info I've read this card needs 500w single. I think the Mac Pro power supply is around 900w

so it.....May...work., if you want to try a 2nd power supply that fits the 5.25" hard drive bay (e-power?).Unfortunately, I don't know exactly how much reserve

power your mac Pro's power supply has. Asking it to supply 500w on top of what your mac pro demands could be too much for it to handle. In your price

range, officially, you'd have the 5770 which has about 1 gig of video ram. I think I paid around $599 for my Sapphire 7950 HD mac version, so that's out

your best bet, I suppose is to see if you can find a PC card that has been flashed to work with Mac. I think MacVidCards provides such a service. Bear

in mind that Apple will not support such a card if it fails.

That is all

JB

Why? do you use FCP-X? that will benefit from two. Also gaming in Windows where you can use Crossfire

You have two 6-pin power feeds so you will need a small 450W PSU - those come with two 8-pin and two 6-pin.

Those can often fit in the optical drive bay and cost $25-75 range.

"500W" is NOT for the card! that is the minimum PC PSU only!

when buying look for card that uses only two 6-pin and not an 8-pin power.

75W for the PCIe slot, and 150W from two 6-pin cables, most GPUs fall into the 200-250W at maximum stress levels8-pin is basically two 6-pins and 150W feed

> we CrossFired a pair of Radeon R9 270s in our 2010 Mac Pro tower. Under Windows 7 64bit Ultimate, it registered 145 FPS in the Diablo test.

http://barefeats.com/tube06.html

Keep in mind that the Mac Pro tower can't feed enough power to the dual 980s, dual 290Xs, or dual 7950s.

We used an auxillary power supply to compensate.

For the hard core GPU rendering, there are external expansion boxes with their own power supplies.

In an earlier article, we featured the Cubix Xpander which facilitated the connection of 5 GPUs to the Mac Pro tower.

• If you favor an AMD GPU like the Radeon R9 290X, MacVidCards can modify it to run at PCIe 2.0 bandwidth in your Mac Pro tower.
• The Sapphire Radeon R9 7950 Mac Edition is available from OWC and TransIntl.

February 6th, 2015 -- Dual GeForce GTX 980s vs other Dual GPUs running multi-gpu 'aware' apps

February 6th, 2014 -- (UPDATE) GeForce GTX 980 GPU versus 8 other GPUs running Games and OpenGL Benchmarks

January 29th, 2015 -- GeForce GTX 980 vs 9 other GPUs running Resolve, LuxMark, and Octane Render

December 28th, 2013 -- Does Final Cut Pro X 10.1 render faster on Mac Pro towers with Dual AMD GPUs? What about Motion 5.1?

Things to keep in mind:

The Radeon R9 280X we used was 'un-flashed.' It booted OS X fine but there was no startup screen. Also, when we checked the speed of CPU-to-PCIe-to-CPU communication, it appeared to be running in PCIe 1.0 mode instead of PCIe 2.0. However, unless the GPU intensive app saturates the PCIe 1.0 bandwidth, it will not run any faster in PCIe 2.0 mode. http://barefeats.com/tube12.html

Which is one reason why you might want to buy pre-modified cards from http://www.macvidcards.com

.

Ok, I could not find the exact number of Watts the card needs but I did find a page saying it uses 2 x 6 pin PCIe cables. A 6 pin PCIe cable can provide up to 75 watts, an 8 pin cable can provide up to 150 watts and the PCIe slot itself can provide up to 75 watts. Therefore this card might need between 150w and 225w, likely the load will vary between those figures depending on how hard it is working but should never exceed 225w.

While the Mac Pro has a 900w power supply that 900w is shared by all the devices in the Mac Pro. The Mac Pro only has 2 x 6 pin PCIe power leads. So a Mac Pro can provide 75w per PCIe slot, and add up to 2 x 6 pin power leads each of which also provides 75w. This means a video card which needs 2 x 6 pin leads might need up to 3 x 75w or 225w in total which the Mac Pro can provide. However if you want two of these cards as the Mac Pro only has two of those 6 pin cables it will not be able to supply enough power to the second card.

The following theoretical configurations would be posible

Card does not need any PCIe cables, i.e. card needs ≤ 75w (total ≤ 75w) = 2 x cards is possible (e.g. a GT-120)

Card needs 1 x 6 pin PCIe cable i.e. card needs ≤ 2 x 75w = (total ≤ 150w) 2 x cards is possible (e.g. Radeon 5870)

Card needs 2 x 6 pin PCIe cables i.e. card needs ≤ 3 x 75w = (total ≤ 225w) 1 x card is possible (e.g. Radeon HD 7950)

Card needs 1 x 6 pin PCIe cable + 1 x 8 pin cable i.e. card needs 2 x 75w + 1 x 150w (total ≤ 300w) = no card is possible

Card needs 2 x 8 pin PCIe cables i.e. card needs 1 x 75 + 2 x 150w (total ≤ 375w) = no card is possible

As the Mac Pro itself cannot provide enough power for two of these R9 270x cards there are two options to provide extra power. Either disconnect the built-in DVD drive and use both power leads from the optical bays with cable adapters i.e. 'steal' power from the optical bays, or use an external power supply.

I am not convinced even Final Cut Pro X will see any benefit from having two cards. Apple specifically added support for two cards in the new Mac Pro but that was for their own custom AMD FireCore cards and not as a generic capability. You therefore might only see a benefit in Windows and only if using the crossfire connector.

From other sources I get the impression that an R9 270x is roughly equivalent to a Radeon HD 7950, and that a R9 280x is roughly equivalent to a Radeon HD 7970.