Have a couple old pirated e-textbooks as .pdf files on my PC from uni, several hundred pages with color images, and they are mostly under 50MB, averaging about 30MB. 1GB is a little over a thousand MB (1024) so 1 would maybe hold a bit under 50 or so each? So times 64 that, a hell of a lot. Several thousand total, at least, as size varies.
Have a couple old pirated e-textbooks as .pdf files on my PC from uni, several hundred pages with color images, and they are mostly under 50MB, averaging about 30MB. 1GB is a little over a thousand MB (1024) so 1 would maybe hold a bit under 50 or so each? So times 64 that, a hell of a lot. Several thousand total, at least, as size varies.
PDF is super overkill for ebooks. Mobi or epub are usually <5mb per book (usually around 1mb)