From: Joachim Berdal Haga Date: Mon, 03 Jul 2006 13:32:42 GMT Subject: Re: Compression speed for large files Message-ID: <44A91C7A.6090902@fys.uio.no> In-Reply-To: <81b0412b0607030503p63b4ee31v7776bd155d3dab29@mail.gmail.com> Alex Riesen wrote: > On 7/3/06, Joachim B Haga wrote: >> So: is it a good idea to change to faster compression, at least for >> larger files? From my (limited) testing I would suggest using >> Z_BEST_COMPRESSION only for small files (perhaps <1MB?) and >> Z_DEFAULT_COMPRESSION/Z_BEST_SPEED for >> larger ones. > > Probably yes, as a per-repo config option. I can send a patch later. If it's to be a per-repo option, it's probably too confusing with several values. Is it ok with core.compression = [-1..9] where the numbers are the zlib/gzip constants, -1 = zlib default (currently 6) 0 = no compression 1..9 = various speed/size tradeoffs (9 is git default) Btw; I just tested the kernel sources. With gzip only, but files compressed individually: time find . -type f | xargs gzip -9 -c | wc -c I found the space saving from -6 to -9 to be under 0.6%, at double the CPU time. So perhaps Z_DEFAULT_COMPRESSION would be good as default. -j