MP 1,1-5,1 Macpro with 3 external displays

[Pilo Adami]

I'm looking to add a 3rd monitor to my set up. I'm currently running:

Macpro 5.1 early 2009 with an ATI Radeon HD 5870 1024 MB

1st monitor - Mindisplay port adaptor to HDMI into an ultrawide LG running SwitchResX4 for maximum resolution

2dn monitor - DVI out into DVI in a DELL monitor



There's another minidisplay port available so I've tried connecting an adaptor out into HDMI into a BENQ monitor with no avail, the macpro seems to only run 2 monitors at a time, is there a solution for this or would I have to purchase another graphics card?



I've also tried displayport adaptor out into HDMI and no success.



Many thanks

 

[Ludacrisvp]

It’s the card not the Mac that is the limit. however the 5770 and 5870 were able to run 3 displays. You likely just need to get a true active adapter for display port to hdmi or dvi if desired.
active adapters and passive adapters for DisplayPort behave differently.

 

[Pilo Adami]

Hey Luda, thanks for your reply.

Update on this:

I've ordered an active HDMI adapter from amazon https://www.amazon.co.uk/gp/product/B01GYAW3V8/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

Unfortunately I can't get all 3 screens to work, I know the adapter works cause I can have both HDMI on minus the DVI, or DVI + HDMI (active or passive) but not all 3, after turning the 3rd screen with active HDMI on it all I get is 'no cable connected'

Not sure where to go from there, if anyone has any insights please let me know, I'm suspicious either my video graphics doesn't support 3 external screens or the adapter is not a 'legit' active one

 

[joevt]

Hey Luda, thanks for your reply.

Update on this:

I've ordered an active HDMI adapter from amazon https://www.amazon.co.uk/gp/product/B01GYAW3V8/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

Unfortunately I can't get all 3 screens to work, I know the adapter works cause I can have both HDMI on minus the DVI, or DVI + HDMI (active or passive) but not all 3, after turning the 3rd screen with active HDMI on it all I get is 'no cable connected'

Not sure where to go from there, if anyone has any insights please let me know, I'm suspicious either my video graphics doesn't support 3 external screens or the adapter is not a 'legit' active one

To be sure a DisplayPort to HDMI adapter is active, find one that does HDMI 2.0 (4K 60Hz) because passive adapters are limited to HDMI 1.4 (4K 30Hz).