<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><meta content="text/html;charset=UTF-8" http-equiv="Content-Type"></head><body ><div style='font-size:10pt;font-family:Arial,Helvetica,sans-serif;'>Thought the below might be of interest to some. The last is the best :-) Hardware and clients identical, octo 4GHz, test load is one yoshimi with jack_keyboard driving by way of a passthrough mididings.<br><div><br></div><div>----------------------------</div><div><br></div><div>Item one is vanilla distro jack2, run like this:</div><div><br></div><div><div>jack_control start</div><div><span style="font-size: 10pt;">jack_control ds alsa</span></div><div>jack_control dps device hw:SB</div><div>jack_control dps rate 48000</div><div>jack_control dps nperiods 2</div><div>jack_control dps period 128</div><div>jack_control dps midi-driver seq</div><div>jack_control dps inchannels 2</div><div>jack_control dps outchannels 2</div><div>jack_control eps realtime true</div><div>jack_control eps realtime-priority 50</div><div>jack_control eps clock-source 1</div></div><div><br></div><div>The above is as low in reported latency I could go, 5.33ms, using every optimization I know of via the Arch wiki and realtimeconfigquickscan and other sources. Running load-less, it gives me usage ranging 0.9 through 1.4%, usually hanging in at 1.3%. With the test load, it tends to sit at 10% and rise with stress. A few xruns every once in a while are inevitable, even when the test load is delivering only silence. Nice tone quality.</div><div><br></div><div>-----------------------------</div><div><br></div><div>Item two is jack1-git, compiled with Zita libraries engaged, run like this:</div><div><br></div><div>nohup schedtool -R -p 50 -e /usr/bin/jackd -A SB -R -c h -X alsa_midi -d dummy -r 48000 -p 32 &</div><div><br></div><div>Reported latency is 2ms. Load-less, usage rating is 1.3% through 29%, usually hanging in at 1.4% or so. With the test load, it sits at 31.2% at silence. No xruns. But no actual sound came out :-)</div><div><br></div><div>-----------------------------</div><div><br></div><div>Item three is jack1-git, Zita libraries present but not used, run like this:</div><div>nohup schedtool -R -p 50 -e /usr/bin/jackd -R -c h -X alsa_midi -d dummy -r 48000 -p 32 &</div><div>nohup schedtool -R -p 50 -e /usr/local/bin/zita-j2a -d hw:SB</div><div><br></div><div>2ms reported latency. Loadless usage is 20%. With test load, 25-33% at silence. No xruns. Distorted sound.</div><div><br></div><div>------------------------------</div><div><br></div><div>Item four is jack2 vanilla distro, run like this:</div><div><br></div><div><div>jack_control start</div><div><span style="font-size: 10pt;">jack_control ds dummy</span></div><div><span style="font-size: 10pt;">jack_control dps rate 48000</span></div><div>jack_control dps nperiods 2</div><div>jack_control dps period 32</div><div><span style="font-size: 10pt;">jack_control dps inchannels 2</span></div><div>jack_control dps outchannels 2</div><div>jack_control eps realtime true</div><div>jack_control eps realtime-priority 50</div><div>jack_control eps clock-source 1</div></div><div>schedtool -R -p 50 -e /usr/bin/a2jmidid</div><div>schedtool -R -p 50 -e /usr/local/bin/zita-j2a -d hw:SB</div><div><br></div><div>2ms reported latency. Loadless usage 3.8 to 4.3%. With triple test load (three Yoshimis which is actually SOP for this rig), 4.5-5.5% at silence. No xruns. Wonderful sound, and no xruns with that triple load being pushed.</div><div><br></div><div>Will be starting rigorous testing at lower latencies soon, but I have an instrument which has to sing first :-)</div><div><br><div id=""><p class="MsoNormal"><font face="serif,times new roman"><i><font color="#660000" size="3">Jonathan E. Brickman</font></i></font><font face="tahoma,arial,helvetica,sans-serif"><font face="serif,times new roman"><i><font color="#660000"><br>Ponderworthy Music<span style="font-size: 10pt;"> | jeb@ponderworthy.com</span><a href="mailto:jb@dcstopeka.com"><span style="font-size: 10pt;"></span></a></font></i></font><span style="font-size: 10pt; color: rgb(67, 32, 3);"><font face="serif,times new roman"><i><font color="#660000"> | (785)233-9977 | <a target="_blank" href="http://ponderworthy.com">http://ponderworthy.com</a></font></i></font><br></span></font></p></div></div></div></body></html>