From: Joachim Berdal Haga Date: Tue, 04 Jul 2006 05:42:03 GMT Subject: Re: Compression speed for large files Message-ID: <44A9FFAB.1010708@fys.uio.no> In-Reply-To: Linus Torvalds wrote: > > On Tue, 4 Jul 2006, Joachim Berdal Haga wrote: >> Here's a test with "time gzip -[169] -c file >/dev/null". Random data >> from /dev/urandom, kernel headers are concatenation of *.h in kernel >> sources. All times in seconds, on my puny home computer (1GHz Via Nehemiah) > > That "Via Nehemiah" is probably a big part of it. > > I think the VIA Nehemiah just has a 64kB L2 cache, and I bet performance > plummets if the tables end up being used past that. Not really. The numbers in my original post were from a Intel core-duo, they were: 158/18/6 s for comparable (but larger) data. And on a P4 1.8GHz with 512kB L2, the same 23MB data file compresses in 28.1/5.9/1.3 s. That's a factor 22 slowest/fastest; the VIA was only factor 18, so the difference is actually *larger*. -j.