I was trying some blurays on a PC that I am going to use with my projector outdoors, and I decided to check the cpu usage. I felt what I was seeing was pretty high. The cpu is an E2180, and the video card is a 4550. While playing Back to the Future, the usage was around 60 ~ 66%. This was with TMT3 and TMT5. I tried PDVD 10 and got around the same results, but I did see it hit 100% one time. Later I tried Harry Potter and the Deathly Hallows and the average seemed to be around 35%. So, not as high as BttF, but still high from what I'm used to seeing. Not sure what version the drivers were at first, but I updated to 11.6, and it was the same.
I looked up a review of the 4550, and I found a test where a bluray was played and the usage on that system was around 11~18%. Something seems to be going on, but not sure what. BTW, this is on Windows 7 32-bit. Any thoughts?