On Tue, Dec 16, 2003 at 12:33:52AM -0700, Slepp Lukwai wrote: > On Mon, 2003-12-15 at 21:08, Richard Ellis wrote: > > Additionally, why kind of memory do you have attached to the cpu's? > > Mpeg encoding is very memory bandwidth hungry to begin with, and with > > two cpu's trying to eat at the same trough, a not quite as fast as it > > should be memory subsystem can produce results like what you are > > seeing. ...
> ... It's a dual Athlon, which inherently means 266FSB (DDR 266), > though the memory is actually Hynix PC3200 w/ timings set as low as > they go on this board (2-2-2), which gives me about 550MB/s memory > bandwidth according to memtest, with a 13GB/s L1 and something like > 6 or 8GB/s L2. The cache size is 256k/CPU, 64k L1. At 550MB/s, it > SHOULD be able to push enough to keep the frames encoding at 100% > CPU, in theory. Yes, but just one 720x480 DVD quality frame is larger than 256k in size, so a 256k cache per CPU isn't helping too much overall considering how many frames there are in a typical video to be encoded. Plus, my experience with Athlon's is that they are actually faster at mpeg2enc encoding that Intel chips of equivalent speed ratings (the Athlon's 3dnow/mmx implimentation is faster) and so they put a heavier stress on one's memory bandwidth than an equivalent speed Intel chip would. It's possible that 275MB/s per CPU just isn't fast enough to keep up with the rate that mpeg2enc can consume data on an Athlon. Of course, Andrew would be much better suited to discuss mpeg2enc's memory access patterns during encoding, which depending on how it does go about accessing memory can better make use of the 256k of cache, or cause the 256k of cache to be constantly thrashed in and out. > > FWIW, when my desktop machine was a dual PII-400Mhz box, I almost > > always had two mpeg2enc threads eating up 97-98%cpu on both PII > > chips. The few times both cpu's were not fully saturated at mpeg > > encoding was when I'd bother them with something silly like browsing > > the web with mozilla. :) > > Now that's just silly. Why would you hurt the CPUs by running such bloat > as Mozilla? I can't think of how many times Mozilla has gone nuts on me > and used 100% CPU without reason, and you can't kill it any normal UI > way.. Good ol' killall. However, I love it. It's a great browser. Just > rather hungry at times. I suppose there's a reason the logo is a > dinosaur. :> Hmm... Interesting. I've had it sometimes just stop but never go nuts with 100% CPU, and although I usually do CLI kill it if need be, FVWM2's "destroy" window command has never failed to get rid of it if I don't bother to go CLI to do so. In fact, FVWM2's "destroy" has never failed to get rid of anything that went wonky. It's the X windows equivalent to a "kill -9" from the CLI. ------------------------------------------------------- This SF.net email is sponsored by: IBM Linux Tutorials. Become an expert in LINUX or just sharpen your skills. Sign up for IBM's Free Linux Tutorials. Learn everything from the bash shell to sys admin. Click now! http://ads.osdn.com/?ad_id=1278&alloc_id=3371&op=click _______________________________________________ Mjpeg-users mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/mjpeg-users
