"if the buffer is too small to hold the whole thing. It will be constantly recycled and overwritten, so will only ever contain a fragment "

A buffer is a a section of memory, but there are many differing and incompatible technical ways to manage it, among them, lists, 'rings' B-trees, etc.

In the early days of 'the streaming betas' you could set options as to where, and how much memory you could allocate to the buffer - it you were clever you could allocate sufficient to hold the whole thing in one file. Nowadays, such things on most of those programs are 'locked' - at least for the minimalist 'free versions' you must have to access the content anyway - if you pay for the full thing, you may be able to fiddle.

In another thread there were links to 'Pills to Purge Melancholy' files - the text only ASCII files were about 230Kb, the PDFs were about 30Mb - ok, the 'text only' is unlikely to have the music scores, but PDFs, SWFs (Flash) etc all are humongously large - a waste of resources with these proprietary coded formats that you need special readers for - you could probably do the facsimiles pages in Jpeg 2 colour (B&W) for a fraction of the 30 Mb.

"since it loads all the linked ads before displaying the article "

This is, by definition, under the W3 standards, just plain incompetence! It has ALWAYS been recommended that you give the viewer something to read, or look at while the rest of the page is loading! Thus picture 'interlaced formats' etc. The technical stuff has been designed to handle it - but these overpaid boofheads seem to delight in stuffing things up!