As my document grows, so does the number of drawings. I am using PGF/TikZ and each drawing is what is enclosed between \begin{tikzpicture} and \end{tikzpicture}. Every time the document is compiled, so is each of the drawings. I have recently noticed in connection with using the Lindenmayersystems library that memory is an issue! There must be a way of compiling drawings outside a document and have the document refer to the result of that compilation, instead of having the drawing's source code reside in the document. This would allow complex drawings to be compiled, with all available resources brought to bear on compiling that one drawing. Also, how could one have a large document with hundreds of drawings and not have a problem with memory?
I am using Windows 7, MiKTeX 2.9, TeXMaker 3.3.1.
externalizecapabilities (see Mark Everitt's answer), checkout my answer to this question. Here I explain how to precompile the preamble, so that it doesn't need to be compiled on every run. This has reduced the compiling time of my documents to < 1s for medium sized documents (~20 pages). Also, you could look into splitting up your document using\includeand\includeonly, which allows you to split up a document and only compile a part of it in a sensible way.standaloneclass and package. The package provides a\includestandalone{file}which can insert either afile.pdforfile.tex. It can even compile the PDF from the standalone TeX file once and then use the PDF. This speeds things up very much (My thesis drops from 120s to 20s).