Why are all rendered stems more than a collect all and save?

[sirvoice]

When my friend collects all and saves a set to send his vocal stems to me, it is only about 100 - 200 meg.

Yet when he renders all tracks, as stems, it's much larger, like 2 gigs or so.

Why the size difference? Are the same files, quality getting exported?

Thanks

xx

[chapelier fou]

Silence.

[sirvoice]

Oh, of course!

[chapelier fou]

mostly. But also duplicated files, samples, etc...