Why can't we just use different compression levels? Or it wouldn't be hard to build into Windows multiple compress-algorithms. So that fast machines use high co

Why can't we just use different compression levels? Or it wouldn't be hard to build into Windows multiple compress-algorithms. So that fast machines use high compression level or CPU-demanding algorithms, and slow machines use the contrary. Therefore slow machines could still decompress files from faster machines efficiently, because in decompression HDD I/O is the bottleneck [1]. [1] http://superuser.com/questions/135594/what-is-more-important-when-extracting-rars-cpu-or-hdd http://superuser.com/questions/135594/what-is-more-important...