Comment 14 for bug 288570

TK, the interpolation takes place in the computer and the color space coversion is done by the printer (at least for most color lasers and HP inkjets). This does not mean that the full page needs to be stored uncompressed in a file or in memory. Ghostscript for example devides up the page into bands and renders only one band at a time and sends it off to the printer before it renders the next band. In addition print data transfer is often done compressed.

You can see in the upstream bug report in comment #7 (http://bugs.ghostscript.com/show_bug.cgi?id=690133#c7) that Ghostscript 8.62 and older needed only 15 MB as temp file space for the job discussed here, Only after a certain change which the Ghostscript developers have already localized the space need jumped into the order of GB. And the released Ghostscript 8.63 seems to take even more space than earlier and later development snapshots of Ghostscript.