Hi All, I have a Dual 1.8Ghz G5 (3.5GB Ram) that I have connected to an LCD Tv. It is also connected to my Airport Extreme Base Station via Ethernet cable or optional 802.11N Wireless USB Network Adapter. I want to play 1080p mkv files on this computer. The problem is, that when I do play them, the resulting video is unwatchable. It's too choppy and slow. I was wondering if I upgrade the video card from it's stock ATI Card with 64MB of Ram to a Radeon X1900 with 256MB of Ram would this improve the video quality to the point that I wouldn't require having to buy a whole new set-up? I also have the newer Mac Mini (2.66Ghz) and that seems to handle 1080p just fine. When I did a comparison using Activity Monitor between the two computers, I noticed that the CPU load wasn't that much different. I'm assuming that the graphics card is the bottleneck. BTW - I want to keep the mini for my office computer so switching them is not an option. Thanks for your help.