These days, modern filesystem like ZFS has compression and data deduplication (identical data only stored once) support, as well as other useful features such as snapshots and copy-on-write.

Drivespace was what enabled me to play Baldurs Gate 1 back in the day. My specs back then:

• 32MB RAM
• Pentium166 MMX
• 500ish MB drive (My 2GB went bust, so I used an old spare drive for quite a while)
• 16X CDROM
• 2X CD Burner… yarr, that made me a lot of money
• 3dFX Voodoo2 8MB coupled with an ATI Rage Pro
• Soundblaster Live