well i am stumped. i have vegas 8.0c and vegas 8.1 (the 64 bit). i have rendered video on both programs with xp 64 bit and vista ultimate 64 bit. the 8.0c is faster then the 8.1. the results are the same when using xp 64 and when using vista 64. to top it off both versions render faster on xp then on vista. i have tried tweaking and setting preferences on both with the same results. I am not surprised that xp 64 may out perform vista 64 but I would have hoped vegas 64 bit would be at least 20% faster then the 32 bit 8.0c version . any suggestions?