On Sun, Apr 11, 2010 at 4:19 AM, Avi Kivity <avi@xxxxxxxxxx> wrote: > On 04/11/2010 02:00 PM, Ingo Molnar wrote: >>>> >>>> Did you make sure to check your stddev on those? >>>> >>> >>> I'm doing another run to look at variability. >>> >> >> Sigh. Could you please stop using stone-age tools like /usr/bin/time and >> instead use: >> > > I did one more run for each setting and got the same results (within a > second). > >> Yes, i know we had a big flamewar about perf kvm, but IMHO that is no >> reason >> for you to pretend that this tool doesnt exist ;-) >> > > I use it almost daily, not sure why you think I pretend it doesn't exist. > >>> Is this something realistic or just a benchmark thing? >>> >> >> I'd suggest for you to use the default settings, to make it realistic. >> (Maybe >> also 'advanced/high-quality' settings that an advanced user would >> utilize.) >> > > In fact I'm guessing --ultrafast would reduce the gain. The lower the > quality, the less time you spend looking at other frames to find > commonality. Like bzip2 -1/-9 memory footprint. The main thing that controls how much obnoxious fetching of past frames you're doing is --ref. This is 3 by default, 1 at all the faster settings, and goes as high as 16 on the very slow ones. Do also note that at very slow settings, the lookahead eats up a phenomenal amount of memory and bandwidth due to its O(--bframes^2 * --rc-lookahead) viterbi analysis. Just for reference, since you're looking at practical applications, here's approximate presets used by various companies I work with that care a lot about performance and run Linux: The Criterion Collection (encoding web versions of films, blu-ray authoring): Veryslow Zencoder (high-quality web transcoding service): Slow Facebook (fast-turnaround web video): Medium Avail Media (live, realtime HD television broadcast): Fast Gaikai (interactive, ultra-low-latency, web video): Veryfast Jason -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href