From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roger Larsson Date: Fri, 29 Oct 1999 20:16:19 +0000 Subject: Re: [linux-audio-dev] Re: Sync Issues (was Re: External MIDI Sync using Message-Id: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: linux-sound@vger.kernel.org Benno Senoner wrote: >=20 > On Thu, 28 Oct 1999, Paul Barton-Davis wrote: > > to an old ISA-based Diamond Speedstar, the performance of my audio > > stuff has gone down the tubes. i can't do *anything* with X and hope > > to not get dropouts. this never happened with the Matrox card, and i > > am very confident that as soon as Matrox ships me a new one, the > > problem will go away. > > > > right now, my system is essentially useless for audio work unless you > > avoid using X. totally useless. i can't even play WAV files without > > *huge* dropouts, and thats on a *dual* PII-450 ! >=20 > Yes, >=20 > the idiotproof test is the following: > install 2.2.10 + lowlatency patch ( not SMP !), > tune the IDE diskas as described in the README > and run a testsession > if the GFX stress graph is the only bad graph, > then I'm sorry but you have to throw away your videocard if you want > to do reliable low latency stuff. > :-) >=20 Or you can try to find out what part of your video card driver that destroys latency and correct that. You can find out the problematic spot with my patch: latency-profiling-2.2.10-r6.patch [for Linux 2.2.10] I will put it on some own web page at the moment you could get it from: http://www.gardena.net/benno/linux/audio/patches/latency-profiling-2.2.10-r= 5.patch And remove this part of the patch since it is not correct... (you should not be tempted to improve things in an instrumentation patch...) =20 - if (tq_scheduler) + //RL latency improvement, correct? + //RL skip if forced reschedule (a normal will arrive soon...) + if (!current->need_resched &&=20 + tq_scheduler) The results are messages in 'dmesg', latency time and instruction pointers are printed. You then decode the instruction pointers to routine name. =20 /RogerL --=20 The Internet interprets Windows as damage,=20 and routes around it. Roger Larsson Skellefte=E5 Sweden