I recently upgraded my three monitor PC from XP to Vista. The install went smoothly and it booted up fine. So I go into my display settings only to see two of my three monitors available. So I mess with trying to get the other driver to load. I play with the video settings in the BIOS. No luck. As it turns out, the problem is that Vista simplified their display architecture by allowing only one video driver to load:

…the Windows Vista Display Driver Model (WDDM) brings fundamental changes to the management of multiple graphics adapters and external displays. This includes a new restriction, because WDDM drivers do not support “heterogeneous multi-adapter” multi-monitor implementations.

Well, that may be good for them, but it’s surely bad for us. Not all is lost though. Microsoft makes a suggestion:

The user could change the graphics hardware configuration by choosing multiple graphics adapters that use the same WDDM driver. Graphics adapters from the same ASIC family generally have the same graphics driver. In late 2006, each of the major graphics vendors had a single WDDM driver for all supported WDDM graphics adapters.

So it sounds like I just need another NVIDIA card. My PCIe slot is being used by my first NVIDIA card so I just need to get a new PCI NVIDIA card. Ok, no big deal. I call up IT and after a little finagling I walk back to my office with a GeForce FX 5500. Not the greatest card in the world, but it’ll do. I pop it in, start up the PC and am welcomed by this:

Ok, what’s going on now? As it turns out, the 5500 is using a WDDM driver and the 8500 is using the “Version: 7.15.11.5818″ driver. Trying to force one to use the other’s driver just results in a lot of blue screens and other funness. Using a 6200 or another similar card fixes the issue since they use the same driver as the 8500. But say you don’t have that option. What does that leave you with?

If you have another PC or laptop at your disposal, you have a couple options:

1. Maxivista. This is a client/server set of utilities that let you run the client PC as a secondary display device for the server PC. You can use the same keyboard and mouse across monitors/PCs, drag windows across monitors/PCs and use the clipboard across monitors/PCs. It truly feels like a 3rd monitor. That is, if I could get it to work. After installing Maxivista, I still received the “incompatible display adapter” message. No amount of disabling Aero, shutting down Ultramon or reinstalling would make it work. Too bad too.

2. Synergy. This is another great little client/server tool. It’s similar to Maxivista, except for a couple things. Synergy doesn’t act like a secondary monitor. It still displays the desktop from the client PC. It simply lets you share a single keyboard and mouse across multiple computers. It supports full clipboard functionality across computers too (Maxivista costs a little extra for that). But Synergy is totally free! Maxivista definitely is not.

I can definitely see the benefit in simplifying the display driver architecture for Vista. Simple = better when you’re talking about source code. However, in terms of usability this is definitely a step backwards. This only causes pain and configuration issues (and usually expensive new cards) for the user. Maxivista would have been a great substitute if I could have gotten it to work (even though having to disable Aero would have been a shame), but Synergy will still give me the three monitor feel that I wanted.