Perhaps if I had a Cray ...Even with my Core Duo T2500 (2.0 GHz), both CPU cores used by vlc, with dedicated graphics, I can't run 1080p H264 .mkv container files smoothly.
How do I interrogate the files to find that out?You downloaded videos are HD H.264 (x264) files? In that case you cannot play them with your Celeron if you use VLC (not enough CPU power for that).