ATI Radeon HD 5770 and 3 monitors : 2x mini DisplayPort to HDMI, 1x DVI-D to DVI-D

Ah, awesome. Thank you good sir!

I have purchased and setup this:

http://www.newegg.com/Product/Product.aspx?gclid=CjgKEAjw286dBRDmwbLi8KP71GQSJAA Ok4sjTpJLYin-YripmTvfe_81Iw30laauKVO1oGShVO3Y3_D_BwE&Item=N82E16812607036&nm_mc= KNC-GoogleAdwords&cm_mmc=KNC-GoogleAdwords-_-pla-_-Audio+Video+Converters-_-N82E 16812607036&ef_id=UzyhfgAABXDoQdpX:20140702172824:s

On the two DVI ports I have and adapter to VGA and a DVI-VGA cable attaching another monitor.

The computer recognizes 3 displays connected, but the monitor connected through the DP shows no signal.

Is this an issue of not having enough power?

I have tried cycling the ports but to no avail. Any Ideas?

Thanks in advance!

Does each port work by itself?

Does every combination of TWO work OK?

If the problem follows one port, then it may be a port problem or a firmware problem.

If it is a Two-out-of-three issue, that is usually a power problem.

Consider updating to 10.9.4 if you are running something near that -- it is said to fix some multiple-monitor problems.

I am 99% sure that I have verified each port, but will have to re-check tonight.

I have not verified each combination of two.

The monitors themselves definitely all work.

I am running 10.6.8, as much of the software I utilize on the computer is not supported passed that. (Mainly Pro Tools 8 LE)

Here is a run-through of my setup:

• 2006 Quad-Core Intel Mac Pro
• OS X 10.6.8
• ATI Radeon 5770 (PC flash - 2 DVI's)
• 1 DVI monitor, 2 VGA(I plan to upgrade one of these to HDMI in the future)
• Radeon card shows up as 5770 in System Profiler

Not sure if there is any other pertinent info needed.

I will get back tonight after verifying the monitors.

Alright.

I have spent some time cable swapping, and here is what I have found.

• The two DVI ports seem to work consistently. I can switch DVI displays and it still works.
• Every combination of 2 monitors will work, if driven by a DVI port
• There is only 1 monitor that I can test on the DP adapter, it is running true DVI-DVI
• Regardless of combination, DP monitor will flicker once as it is immediately recognized and added to the list of displays, it then goes into standby mode.

I would've thought that if not enough power for the signal was the issue, then it wouldn't be recognized in display preferences. I'm starting to think I'm wrong.

Here is a snapshot of card and displays all connected:

(The Dell SP19 is the DVI monitor, it can also be used as VGA if necessary)

Some poking around on eBay, looking at the flashed 5770 cards has provided a clue:

Ports :

2 x DVI, 1 x HDMI , 1 x DisplayPort

The DisplayPort is supported in Mac OS X 10.7 and newer

DisplayPort requires native DisplayPort monitor, ACTIVE DisplayPort to DVI adapter or DisplayPort to VGA adapter.

With Mac OS X 10.7 and newer this video card will support 3 monitors connected thru:

2 DVI Ports and DisplayPort.

HDMI port is supported but can't be use in 3 displays configurations.

For single or dual monitor setup all ports are supported.

DVI/DVI, DVI/HDMI, DVI/DisplayPort

Does this apply to your situation?

--------

The last two rounds of security updates from Apple have omitted any updates for 10.6.8. 10.6.8 may be a security risk going forward, unless this computer is not connected to the Internet.

Ughh...

I have been weighing whether or not to upgrade to Lion for some time now, but always decide against it because of Pro Tools compatibility.

Upon further inspection of the listing for the card I purchased, I DID in fact find that same line buried in there. Problem solved. For now.

One last question for now:

It says the DVI ports must be used for triple monitor support, I'm assuming that a DVI>HDMI adapter will fine, correct?

HDMI is pretty much just a re-wire of DVI-D signals (except for issues around sound output). The signals and levels are directly compatible. HDMI above 1920 wide (1920 by 1080 = 1080p) is not supported in a consistent way on HDMI, so it is extremely troublesome to go over 1920 wide with HDMI.

Grant, you are a wealth of information, and I am very glad you posted your knowledge in this thread.

Using an ATI 5770, and three monitors has proven to be unstable.

I am using the ACCELL single link active adapter.

My config:

MacPro 2010, ATI 5770, OS X 10.6.8

• A -NEC PA271W Wide Gamut 2560 x 1440 - Connect direct to Mini Display port to monitor's DIsplay port.
• B - Samsung 245T Wide Gamut 1920x1200 - Connected to second Mini Display port via the Accell Active adapter to monitor's DVI.
• C - Samsung 245T Wide Gamut 1920x1200 - Connect to DVI out to monitor's DVI.

Problem: Samsung B, connected to the Accell port would occasional shut off, particularly after long periods of use (as a VFX artist, I sometimes work 18 hours straight). Because it was attached to the Accell adapter, I assumed the adapter had a thermal intermittent.

However, Just now I put Samsung C on the Accell, and Samsung B on the DVI port.

Amazingly, Samsung C is now working on the Accell, and Samsung B is off, connected to DVI.

If I remove the NEC, the other Samsung will work. SO, obviously the ATI card must have some sort of protection that shuts off a third monitor when it must be struggling due to heat or some other load issue.

I am mainly posting this to indicate that in the case of the 5770, an externally powered adapter is probably advised for stability reasons. (I'm not going to get one as I am about to upgrade to an nVidia (GTX 880 when it releases) that has 4 ports.

Thanks again, your posts helped me pinpoint a problem that has been bugging me for awhile.

Regards

Andy

Thank you, Grant, for keeping your cool and continuing to provide useful information. I just wanted to add my successful experience to the forum. Mid-2012 Mac Pro, ATI HD 5770 card, three Dell DVI monitors at 1600x1200. Using the Apple adapters of course did not enable three screens. After reading your posts, I ordered two of the Accell adapters from your list. They arrived today - plugged them in, turned it on and three live screens, just like that!

I am a bit confused as to why the ATI card does not have sufficient power to drive three screens, while using powered adapters that get their power from said card makes it work. If you have an explanation (or a link) I would enjoy understanding this.

Regards

For my time and money, if it comes to "professional flashing PC cards" then it is

http://www.macvidcards.com -

I am a bit confused as to why the ATI card does not have sufficient power to drive three screens, while using powered adapters that get their power from said card makes it work.

from: http://en.wikipedia.org/wiki/DisplayPort#Dual-Mode

Dual-mode DisplayPort (also known as DisplayPort++^[37]) can directly output single-link HDMI and DVI signals using a simple passive adapter that adjusts from the different connector and the lower voltages used by DisplayPort.^[38][39] When a dual-mode chipset detects that a DVI or HDMI passive adapter is attached, it switches to DVI/HDMI mode which uses the 4-lane main DisplayPort link and the AUX channel link to transmit three TMDS signals, a clock signal and Display Data Channel data/clock. Dual-mode ports are marked with the DP++ logo; most DisplayPort graphics cards support this mode.

So the limitation is in the way the Driver circuits are set up. To change to the levels for ultra-reliable operation with multiple interfaces on the card, an ACTIVE adapter uses a new Driver circuit that outputs "real" DVI levels, and picks up the power to drive them off the power pin on the Interface.

Dual-Link DVI has additional problems -- there are not enough output signal pins and they cannot switch fast enough. So a complex conversion is performed in the interface, and many more signals at DVI levels are generated. The electronics to do this is much more expensive than just Driver circuits, so if you go wider than about 1920 wide, you need to more complex (and at about US$100, more expensive) Dual-Link DVI adapter that also requires a USB pigtail for yet more power input.

Apple provides only the Dual-Link adapter because it ALWAYS works, even if it is overkill in some situations.

Hi Grant. Sorry to be another guy taking up your time, but you seem to be the most knowledgeable about this issue. Unfortunately for me I lose you in your explanations as I'm fairly new to this.

I have a ATI Radeon HD 5770 on my early 08 Mac Pro. I've always had 2 monitors hooked up using:

- VGA to DVI into the provided DVI

- DVI to MiniDisplay Port into Provided MiniDisplay Port

So I have an open MiniDisplay Port. I now want to connect a Samsung TV. I bought a cord with HDMI on one end and MiniDisplay Port on the other. And when I turned my Mac on it automatically picked up the TV but now blacked out the monitor that is connected via VGA to DVI.

Any help would be GREATLY appreciated. Thank you very much for your time... And by the way, my brothers name is Grant. 🙂

This is the article that says you can connect two "legacy" (i.e, not DisplayPort or Mini DisplayPort) displays freely, but the third will require an ACTIVE adapter:

Mac Pro (Early 2009), Mac Pro (Mid 2010), Mac Pro (Mid 2012): Issues with three displays and multiple DVI, HDMI connecti…

This is the article with a table of how to connect various displays. But keep in mind that Apple ONLY sells the US$100 ACTIVE Dual-Link Adapter. Third party ACTIVE adapters for displays less that 1920 wide are readily available for about US$30:

Mac Pro (Early 2009), Mac Pro (Mid 2010), Mac Pro (Mid 2012): Supported display configurations - Apple Support

ACTIVE adapters are required, and they will be sold as ACTIVE adapters to justify their about US$30 price.

<http://www.startech.com/AV/Displayport-Converters/Mini-DisplayPort-to-HDMI-Activ e-Video-and-Audio-Adapter-Converter-Mini-DP-to-HDMI-1920x1200~MDP2HDS>