How Do I use an Ati Radeon 4870 HD for 3 Monitors

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Level 1

4 points

How Do I use an Ati Radeon 4870 HD for 3 Monitors

I am new to the Apple world and community. I recently got a new job that requires me to use a Mac Pro. OS X version 10.6.8. 2.66 ghz dual xeon and 32 GB of ram. It has a ATI Radeon 4870 HD. I can run 2 monitors fine using the DVI and Mini DV port ( Using a convertor from apple. ). When I try to use the 2 other HDMI ports for my third monitor, Mac OS wont detect it. The wierd thing is some of the images from certain apps show on the 3rd Monitor.

Under graphics information it shows the Radeon 4870. Under PCIe information it shows the same card. On the back of my machine I have 2 HDMI slots and another lower down with Mini DV and DVI.

The Displays I am running are 3 HP LP2475w Monitors. Running in DVI mode with one converted to Mini DV. The 3rd non working is running in DVI to HDMI but it can be run Straight HDMI if need. Ive tried alot of configuration settings and I can't get the HDMI port to be detected by MAC OS. Ive plugged one in at a time and just the HDMI do not detect.

Please let me know what information is needed to help troubleshoot this better.

Posted on Aug 1, 2012 2:30 PM

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Answer 1

The hatter

Level 9

60,990 points

Aug 1, 2012 2:47 PM in response to vsong

Sounds like a non-Apple flashed 4870, though.

Apple System Profile: does it show MacPro4,1 or 1.1?

Does the 4870 show 1GB VRAM or 512MB?

The ATI Apple 5770 or 5870 might be better fit.

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Answer 2

vsong Author

Level 1

4 points

Aug 1, 2012 3:33 PM in response to The hatter

The hatter wrote:

Sounds like a non-Apple flashed 4870, though.

Apple System Profile: does it show MacPro4,1 or 1.1?

MacPro 4.1

The hatter wrote:

Does the 4870 show 1GB VRAM or 512MB?

512MB

I was told the guy before me got it to work. So I am wondering if he did anything special.

The budget is coming up this year but since this mac is fine, I dont think I can push for an upgrade at work.

Thanks for the information hope this helps.

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Answer 3

The hatter

Level 9

60,990 points

Aug 1, 2012 3:56 PM in response to vsong

A 5770 is $249 or slightly less and in the same dept to me as replacing hard drives, adding some RAM in order to work and because my understanding is it was the first card to support 3 monitors.

The 5770 only requires 10.6.5+ - and the 4,1 had way too many issues with 10.5.7/10.5.8

The 4870 may or may not provide what you need for the software you run, even though 3 yr old machine but 4 yr old plus video card.

flashing:

http://boeglin.org/blog/index.php?entry=entry090918-031702

4870 vs GTX 285 that came out at that time also

http://www.geek.com/articles/games/macpro-whats-better-ati-radeon-4870-or-nvidia -gtx-285-20090720/

The default card was Nvidia GT120 and req'd no power cables and popular way to support more displays.

People were running DUAL 4870s to support 3rd monitor though back then:

http://forums.macrumors.com/showthread.php?t=665034&page=10

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Answer 4

vsong Author

Level 1

4 points

Aug 1, 2012 4:22 PM in response to The hatter

Thanks for the information. I may try these if I can't get the company to buy me a new video card.

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