The specific benchmark of 500MB was not arbitrary. It aligned with the storage capacity of optical media (CD-Rs) and the limitations of early USB storage.
Original Size: ~4.2 GB Compressed "Rip" Size: ~300–400 MB San Andreas is the quintessential example of the "rip" technique. The game contains hundreds of megabytes of radio stations, voice acting, and cutscenes. Highly Compressed Ps2 Games Under 500mb
He scoured the deep forums, the ones with scrolling "Under Construction" banners and neon green text. He wasn't looking for the blockbusters that filled DVDs; he was hunting for the "ghosts"—games stripped of their cinematic bloat, downsampled until they were pure, jagged adrenaline. The Discovery A buried thread titled "The 500MB Holy Grail." The File: A .7z archive that defied physics. The game contains hundreds of megabytes of radio
What are Compressed PC Games and Does it Really Work? - RSSing.com