If the file is any size above 500mb, even at lowest quality when converting my computer cant do anything else while it converts, dunno what resource it is using, because my cpu is at only 10%, disk usage 0%, gpu 0%. but the fans are going wild for some reason. Cant browse anything else while its converting....so yea im not gonna use this much except for the small files (below 100mb its superfast on low quality for audiobooks ect)