A performance test done with 500 RFC documents (RFC 1500-2000), totaling about 64MB of plain text. My computer is Intel® Core™2 Duo CPU T5450, 1.66GHz, 3325.09 bogomips. Hatta version 1.3.2dev (changeset 463:74d02975ca4d).
real 0m27.771s user 0m25.386s sys 0m1.848s
I have downloaded 4900 text documents with the recent RFCs, totalling 240MB of plain text data, and used them as pages for Hatta (used changeset d95504d99157 of development version).
Now, over an hour of CPU time (translates to several hours of work) is not a reasonable figure – but 4900 pages is not a reasonable figure either, at least not all at once. Normally you'd have them added one by one and indexed as they go. The good news is that the operation of all the rest of the wiki doesn't suffer.
The performance of indexer has improved greatly since version 1.3.2 – it can still take several minutes for a huge database like above (as opposed to almost an hour previously), and is done incrementally only for the modified pages.