[mkgmap-dev] Memory limits for mkgmap and splitter

Fri Aug 7 15:15:14 BST 2009

On Fri, Aug 7, 2009 at 2:56 PM, Chris Miller<chris.miller at kbcfp.com> wrote:

> I've got 4 cores (8 with hyperthreading) so this is something I'm acutely
> aware of. Watching my PC churn away at only 12.5% CPU for a few hours isn't
> my idea or resources well spent! Unfortunately there's no quick win because
> the XML parsing is very linear, but I have already been considering various
> options and certainly plan to give them a try at some point. I've got quite
> a few other improvements planned that'll come first though.

Just out of interest, what performance gains (or disadvantages) would
there be to working with uncompressed files, instead of bz2 and gz
files?

Would this be faster for those of us with copious amounts of disk
space, or would the extra IO negate any CPU-related performance gains?

I know that Osmosis performance on multi-core systems can apparently
be improved by piping the OSM file through a decompression program,
but I assume that would not be practical for Splitter which must make
several passes through the file.

Cheers.