ATI Radeon 5770 Eyefinity with three monitors using passive DP to HDMI cable

Question

I'm still not clear if my passive DP to HDMI cable is sufficient.Here's the setup:

2 x DVI monitors
1 x HDMI monitor attached to 5770's Display Port with a passive DPI to DP cable

Any two monitors work fine, but can't get all three going together. Should this work, or do I need an "active" DP to HDMI converter or native DP monitor?

--- Thanks!

Answer 1

I'm in Ubuntu, but this seems like an OS agnostic problem. I tried the exact same thing as you with two DVI and one DisplayPort → HDMI. No matter what I tried, the third monitor would not receive input.

I then switched the DisplayPort → HDMI to DisplayPort → DVI and everything worked fine. The DisplayPort → DVI is passive (I think) and it seems to be ok.

So the issue here has something to do with DisplayPort → HDMI.

Answer 2

This won't work with a stock 5770 - ANY output over two has to be active DisplayPort. Sapphire does have a variant (the FLEX series) that will accomplish this passively, but they do this by lowering one of the DVI outputs to single-link.