I'm very impressed..

[dAVID_]

Well, I downloaded a torrent that linked to an All-In-One Half-Life game package. So, I downloaded it, 2.55 GB.

The uncompressed size is 35.7 GB. I don't have any idea of what installer program they used, but WOW!

 

[DinohScene]

Either it contains a lot of fake zeroes or it's heavily damaged.
Either way I wouldn't trust it.

 

[migles]

what dinoh said
but concidering that they share a lot of the same stuff, like same engine, enemies, textures etc, i woldn't be surprised if ya can get really that small
fit girl usually do crazy repacks like that, but half life doesn't seem to be one of them
i do have the orange box in retail, which is 2 dvd's for all half life games + tf2 + portal. while portal and tf2 are visually and sound totally different aside from the engine, the half life games do share plenty of data

BTW, make sure you didn't get a "RIP" version which removes plenty of data like music

 

[Deleted-355425]

The ordinal cds were only 700mb so it probably is legit.

 

[The Real Jdbye]

Well, I downloaded a torrent that linked to an All-In-One Half-Life game package. So, I downloaded it, 2.55 GB.

The uncompressed size is 35.7 GB. I don't have any idea of what installer program they used, but WOW!

I have come across a couple archive formats in warez releases that have insane compression, but of course it depends on what kind of data you're compressing. If the data is already heavily compressed (PNG/JPG files, most video/audio formats) then additional compression won't be very effective. Text compresses extremely well, and uncompressed image formats like BMP and GIF compress very well as well. Raw video of course compresses very well, but that's rarely used.
I have no idea what kind of file formats those games use, but as they are older games they probably aren't using the latest and greatest compression formats, so I wouldn't be surprised if it's legit.