We have two older Dell Optiplex 990 systems with AMD Radeon HD 6450 graphics adapters that have a DisplayPort and DVI-I dual adapters. Both systems currently support two 1920x1200 monitors and we are interested in moving to three. The AMD site says that the 6450 supports "up to 3" monitors, but apparently some versions of the 6450 have three connectors. The DVI-I connector is of the dual type and is described as dual, but many of the DVI splitters I find are clearly for replicating the same content on both monitors, which is of no interest to us. I have been told on another forum, not very authoritatively, that the third monitor would have to use a spliter on the DisplayPort connector.
Does anyone know for sure whether we can support three monitors with this card and, if so, which connector we need to use (or even a recommended connector)?
The AMD site only reflects information for their retail video cards, not the Dell OEM (original equipment manufacturer) video cards. As you can see in the picture below, Dell sold two versions of the OEM AMD Radeon HD 6450, none had DisplayPort =
If your video card is actually the bottom one, then no, you cannot split the DVI signal to two monitors unless you are cloning or mirroring them. I have never heard of a DisplayPort splitter. You should consider getting a video card with three dedicated video out ports.
The card looks like the lower one, except that it is DisplayPort instead of HDMI, i.e., notch only on one side. Both systems are a few years old. One system is actually in transition to a new system which has a GeForce GT 720 with DVI-D dual, HDMI, and VGA connectors. That is the original target for the three new monitors, but in arranging to get cables for it, I kept running into VGA to HDMI or DP adapters which were limited to 1920x1080. The card itself says it will support VGA 2048x1536 and it may be that I just haven't found the right cable, but I thought that if I could solve the issue of splitting the DVI that might keep me from having to use the VGA, which, being analog, seemed like a less good idea anyway. If I could solve the problem for the GT720 confidently, so that system was ready to go when the boxes get swapped, then I wouldn't absolutely have to solve the problem for the existing 990 which is being replaced.
The other 990 is not yet scheduled for replacement, although I could sure use more memory. But, there will be an extra monitor when the swap is complete, so I thought it would be nice to explore three.