follow up to question....

maybe some of you can suggest...
i'd be looking for a scenario where i had a NETBOOK of some sort (skype/internet/calendar) that i could plug a midi controller into (m-audio usb controller, usb midi cable, or other) and playback a variety of softsynths from the internal soundcard at LOW LATENCY. it would be cool to have a basic writing program too...

I'm assuming that you're considering also a Windows netbook. My system works pretty well and is pretty painless :

Asus 1005HAB netbook
2GB RAM
internal soundcard using Asio4All (as driver for low latency)
Cantabile VST host (to run multiple applications at once)

As mentioned in various posts, you need to lower the internal Pianoteq sample rate to 24K or below in order to get good performance. For live, this is just fine AFA sound quality. You might want to search the keyword 'netbook' to check out various tweaks and settings.

maybe some of you can suggest...
i'd be looking for a scenario where i had a NETBOOK of some sort (skype/internet/calendar) that i could plug a midi controller into (m-audio usb controller, usb midi cable, or other) and playback a variety of softsynths from the internal soundcard at LOW LATENCY. it would be cool to have a basic writing program too...

right now, i'm on macbook pro, with logic 9 and mainstage, and have an external audio device and blah blah blah... too heavy, too expensive, too precious to throw into a backpack on a greyhound bus. i need something that i can replace easily (i.e. a $300 netbook) and that i can REBOOT if replaced... (reinstall simply and effortlessly).

ok. thanks... sorry to be the 'new guy' here... but you should all really start a website! there are tons of people wanting what you're working on!

1. what is the hardware that you are using - eeepc? which model? does it matter, or does it matter more which Linux kernel? have you tried this configuration on other hardware - i.e. I AM CURIOUS TO KNOW WHICH NETBOOK I SHOULD BUY ...

2. Linux Build - which kernal are you using...? and HOW ON EARTH can i set it up so that it works as well as it does for you? i am a total beginner with this, so please be gentle!

3. what other software is required, and how can i install? i read about JACK and other patches to linux...

4. is it possible that you can compile a boot file to obtain the same settings? in the same machine? on a different machine?

you have really done alot of work here, and something that i'm sure ALL pianists would LOVE to get their hands on... you should be rewarded for your hard work!

please post a reply.
johnroney

Afterwards I have these RealTime-priorities

# ./rtirq.sh start
Setting IRQ priorities: start [rtc] irq=8 pid=371 prio=90: OK.
Setting IRQ priorities: start [snd] irq=16 pid=867 prio=85: OK.
Setting IRQ priorities: start [uhci_hcd] irq=18 pid=862 prio=79: OK.
Setting IRQ priorities: start [uhci_hcd] irq=19 pid=858 prio=78: OK.
Setting IRQ priorities: start [uhci_hcd] irq=23 pid=851 prio=77: OK.
Setting IRQ priorities: start [i8042] irq=1 pid=364 prio=75: OK.
Setting IRQ priorities: start [i8042] irq=12 pid=363 prio=74: OK.

Before all IRQs had the same priority:

# ./rtirq.sh status
  PID CLS RTPRIO  NI PRI %CPU STAT COMMAND
   91 FF      50   -  90  0.0 S<   IRQ-9
  363 FF      50   -  90  0.0 S<   IRQ-12
  364 FF      50   -  90  0.0 S<   IRQ-1
  371 FF      50   -  90  0.0 S<   IRQ-8
  851 FF      50   -  90  0.0 S<   IRQ-23
  858 FF      50   -  90  0.0 S<   IRQ-19
  862 FF      50   -  90  0.0 S<   IRQ-18
  867 FF      50   -  90  0.0 S<   IRQ-16
  917 FF      50   -  90  0.0 S<   IRQ-14
  918 FF      50   -  90  0.1 S<   IRQ-15
2559 FF      50   -  90  0.0 S<   IRQ-28

Ready to play now ...

Is the latency now 2.9ms or 1.5ms when I choose 44100Hz and 64 samples with device type ALSA?

It is 2.9ms. With jack, it depends on the number of periods/buffer you choose. With 2 periods/buffer and a block size set to 64 samples/period you get 1.5ms, with 3 periods/buffer you get 2.9ms, etc. with n periods you get (n-1)*1.5 ms

Hmh, I'm using Alsa directly without jackd, so I can't choose the number of periods. I guess, 2 periods is ALSA's default then, when 2,9ms is the right value. Thanks for clearification, the GUI is a little confusing, but the README-LINUX.txt nails it.

Is the latency now 2.9ms or 1.5ms when I choose 44100Hz and 64 samples with device type ALSA?

It is 2.9ms. With jack, it depends on the number of periods/buffer you choose. With 2 periods/buffer and a block size set to 64 samples/period you get 1.5ms, with 3 periods/buffer you get 2.9ms, etc. with n periods you get (n-1)*1.5 ms

- with Jack or Alsa, pick-up buffer sizes that are multiple of 64, as
   Pianoteq prefers those sizes. With the Alsa driver, the latency is
   2 times the buffer size (a buffer of 64 samples at 44100Hz gives a
   latency of 2.9 ms).

Is the latency now 2.9ms or 1.5ms when I choose 44100Hz and 64 samples with device type ALSA?

Have you tried, by the way, using other music programs with the soundcard in the loop? Do monophonic instruments fare better in terms of latency?

I have very low latency with usb-audio now! The kernel-module("driver") snd-usb-audio has an option to process USB in shorter chunks. The default number of packs is 8 which I now set to 1:
options snd-usb-audio nrpacks=1
(in /etc/modprobe.d/alsa-base.conf to make it bootfix)

The smaller this number is, the better the latency. - Now I feel "connected" with my instrument, which is only possible with low latencies IMHO.

The only other audio-app I tested a few weeks ago was the organ-sim beatrix. Though I only had a standard debian-kernel at that time, it had good performance (and an amazing good sound). With my new RT-environment it will be pleasure, I guess.

cheers

The v3.0.4 is now updated, and hopefully that bug is fixed.

Yes, it is!
A few things I noticed: CPU identification under Pianoteq now shows
Intel(R) Atom(TM) CPU N270 @ 1.60GHz, M12/S2/F6, x2
Before the fix there was  "x1" at the end of the line.

Now I can activate Multicore rendering, and when I do it, I see
"Multi-core: got real-time scheduling with priority 65" at the command line.

The performance is better with Multicore rendering ON. I guess that is the expected behavior. One step more in the right direction! Thanks for your great customer support!

Why should USB1.1 not be able to provide low latency? Is this documented somewhere?

My impression is that usb 1.1 is just slower for any data through-put, whether one is moving files over a usb cable or sending out midi data. That's the reason that the standard was upgraded to 2.0.  And I suspect that PianoTeq, particularly, with its high polyphony abilities, might increase the latency.

But I hope I'm wrong. I want you to be able to get this up and running. (So we can all copy your settings and have a portable PianoTeq system without having to build a rack system.)

Have you tried, by the way, using other music programs with the soundcard in the loop? Do monophonic instruments fare better in terms of latency?

we made a stupid mistake that prevents the linux version from considering your configuration as eligible for multicore rendering. We will update version 3.0.4 very soon on our site

The v3.0.4 is now updated, and hopefully that bug is fixed.

why should USB1.1 not be able to provide low latency? Is this documented somewhere?

Thanks, but it seems that link is outdated (2004/2005). I'm not aware of any other drivers/kernelmodules for USB audio-devices than snd_usb_audio under Linux. Every USB1.1 audio device should work. USB2.0 is AFAIK more problematic, because this standard is more open and sometimes firmwares have to be loaded. I never heard about latencies of snd_usb_audio, but maybe I haven't googled enough ;-)   

Troughput of USB1.1 should not be the problem, if the following is approximately right: 44,1 kHz * 16 bit = 0,7 Mbit/s. But USB1.1 provides 12 Mbit/s, which is more than enough.