3 monitors on Radeon 5770

[pianoman88]

I have monitors attached through the DVI and one of the mini ports using a mini-to-DVI adapter I purchased from Apple.

Can I purchase another adapter or would it be better if I plugged a monitor directly into the mini port?

 

[bax2003]

Scenario 1
1. DVI - DVI
2. Mini DP - DP (cable Mini DP to DP)
3. Mini DP - Active DVI Adapter or Active DL DVI Adater for resolutions greater than 1920x1200

Scenario 2
1. DVI - DVI
2. Mini DP - Active DVI Adapter or Active DL DVI Adater
3. Mini DP - Active DVI Adapter or Active DL DVI Adater

If you convert any of Mini DPs to HDMI, you loose second Mini DP, even if you connect USB powered DVI adapter, you cannot use it. It is or DP to HDMI or DP to DVI, cannot use both. Tried it both on 5770 and 5870 and one shuts down the other.

 

[Bwa]

You can drive three DVI monitors from a single 5770. I have done it for years.

But you must use two active DVI adapters.

 

[akadmon]

Scenario 1
1. DVI - DVI
2. Mini DP - DP (cable Mini DP to DP)
3. Mini DP - Active DVI Adapter or Active DL DVI Adater for resolutions greater than 1920x1200

Scenario 2
1. DVI - DVI
2. Mini DP - Active DVI Adapter or Active DL DVI Adater
3. Mini DP - Active DVI Adapter or Active DL DVI Adater

If you convert any of Mini DPs to HDMI, you loose second Mini DP, even if you connect USB powered DVI adapter, you cannot use it. It is or DP to HDMI or DP to DVI, cannot use both. Tried it both on 5770 and 5870 and one shuts down the other.

Scenario 1 is working for me with the Apple DL-DVI to mDP adapter, but not with an active DVI to mDP adapter I got from Amazon (Startech), even though the third monitor is only 1920x1200 (the adapter should work!). What brand of active DVI to mDP adapter are you using?

 

[bax2003]

Scenario 1 is working for me with the Apple DL-DVI to mDP adapter, but not with an active DVI to mDP adapter I got from Amazon (Startech), even though the third monitor is only 1920x1200 (the adapter should work!). What brand of active DVI to mDP adapter are you using?

Adapter from Sapphire.

Very similar scenario:
http://www.youtube.com/watch?feature=player_detailpage&v=rgbnE_NVuVY#t=171s

 

[akadmon]

Adapter from Sapphire.

Very similar scenario:
http://www.youtube.com/watch?feature=player_detailpage&v=rgbnE_NVuVY#t=171s

After a couple of days living with it, I find that the Apple DL DVI-->mDP cable is flaky. The signal on the third monitor keeps dropping out every few minutes, requiring the monitor to be power cycled. Today I got a Sapphire active DVI-mDP adapter (max 1920x1200, but a quarter of the cost of the Apple cable) and so far it's been flawless. Thanks!

 

[bax2003]

As it turned out, Apple DL DVI-->mDP cable is flaky. The signal on the third monitor keeps dropping out every few minutes, requiring the monitor to be power cycled. Today I got a Sapphire active DVI-mDP adapter (max 1920x1200, but a quarter of the cost of the Apple cable) and so far it's been flawless. Thanks!

You are welcome

 

[willgreene99]

So in a three monitor setup, the resolution will only be 1920x1200 for the third monitor using the above configurations? Is it possible to drive three apple displays using mdp at the full resolution of 2560x1440? And I think I read that the apple tb displays will not work on mp.

 

[The-Pro]

im using a 5770 with two apple MDP to VGA adapters to power two 23" Acer screen (full HD) and then I have 30" ACD plugged into the DVI port.

 

[akadmon]

So in a three monitor setup, the resolution will only be 1920x1200 for the third monitor using the above configurations? Is it possible to drive three apple displays using mdp at the full resolution of 2560x1440? And I think I read that the apple tb displays will not work on mp.

Yes, but you need two Apple DL DVI-->mDP adapters (2x$99), or two of these (slightly less expensive). I just needed something to drive my 1920x1200 Dell as a third display.

 

[bax2003]

So in a three monitor setup, the resolution will only be 1920x1200 for the third monitor using the above configurations? Is it possible to drive three apple displays using mdp at the full resolution of 2560x1440? And I think I read that the apple tb displays will not work on mp.

To get Dual Link DVI resolutions work from Mini Display Port, you must have Active Dual Link DVI adapters which use aditiotnal power from USB ports (most often). DVI is hungry for more power above 1920x1200.

 

[willgreene99]

To the two posters above ^

That is good info! Thanks for the tip.

 

[nigelbb]

My wife had three monitors on her 5770. The Apple DP->DVI adaptors were very flakey & apparently only certified to work with ACDs. Two USB powered DP->DVI adaptors from Lindy worked reliably.