On Sun, 01 Jul 2007 13:12:28 +0200 cpghost <[EMAIL PROTECTED]> wrote:
> I'm using fan-less Soekris (266 MHz) and EPIA (500 MHz) > boards with -STABLE. Those boards have been emitting a > very high pitched annoying whine, similar to a dog > whistle. Not everyone I asked could hear it, but I was, > and it was driving me crazy for months. > > This whine stopped entirely the moment I put > kern.hz="100" in /boot/loader.conf and rebooted. > Quite relieving! Possibly a beat frequency between the 1kHz default slicing and some faster oscillator on board? You could play around with kern.clockrate, sometimes quite small frequency changes make a difference, especially if it's a harmonic. Default HZ jumped from 100 to 1000 probably around the time when more servers were seen running at nearer 3000MHz than 300 :) > Are there any reasons NOT changing kern.hz from the > default 1000 back to 100? With my typical mix of > desktop apps (EPIA) and networking / server (Soekris), > everything seems to be running just as smoothly with > 100 Hz than with 1000 Hz (testing now for two weeks > without problems). Even playing videos with mplayer > on the EPIA doesn't look different in any way. No problem then, and a lighter interrupt load; probably enough to notice in top. If you want to run dummynet or something else? wanting quicker ticking you could try HZ=200 - 500. 200Hz on my Celeron 300 works well. > Is it okay to stay with 100 Hz with this type of > low-speed CPU/boards? Or are there some compelling > reasons not to? If it's happy, smooth and keeping up, it's fine. Cheers, Ian _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
