|"I was really hoping to see some difference in the performance and quality of my .mkv files. "|
The 8500GT has a first-gen H.264 hardware decoder, so you should already be getting top quality, hardware accelerated video. Windows 7's built in H.264 decoder is fast and knows how to use hardware acceleration, so if you're not already using it, give it a try.
Super PIII | Unlocked ES Tualatin @ 1.8GHz (150x12, 1.65v, 512K L2)
2GB PC2700 | 500GB | Radeon x1950Pro | Apollo Pro 266T | Win 7 Pro