The DP requirement was a major point of all of the initial eyefinity reviews and I've mentioned it on my blog several times. It also says on the product packaging that more than two displays requires additional displays be DP. Having fewer PLLs saves power and die area and most people don't use more than two monitors at the moment. DP runs at a fixed clock regardless of the mode so you can run multiple streams off the same PLL. Non-DP requires a dedicated clock per stream as the clock varies based on the mode. You can use the same PLL if multiple modes share the same clock. Things like PLL sharing are complex to validate and confusing to users since users may run two or more monitors at the same mode, and then try and change the mode on one of the monitors only to have the driver report that it's not possible due to PLL limitations. AMD only officially supports two non-DP monitors with eyefinity for that reason.
Originally Posted by Brane215
Last edited by agd5f; 05-20-2013 at 11:41 AM.