Topic by Quantenirrwisch

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  • Quantenirrwisch
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Topic: Latency Issues despite (appearently?) sufficient processor on linux

Hi guys,
I'm currently planning a "practicing setup" using a Kawai VPC-1 (cause it has like the finest touch ever),  and I was planning to use it with an old lap-top of mine which would then be dedicated to only serve as the piano lap-top (I obviously want to have as few time gone as possible in between sitting on the piano and actually starting playing).
The Laptop is a toshiba tecra, it has 1 GB Ram, and a two Intel Processors with 2.00 GHz frequency. The Soundcard is an Onboard Audio device (I'm thinking about replacing it). I use the Distribution Tango Studio 2.2.

Before Buying all the Stuff, I plugged the laptop to an old yamaha keyboard, which I just use as a Midi controller (via usb) and downloaded the trial version of Pianoteq. While using it with keyboard, I constantly have a Delay, which I defenitely can notice: When I use the Yamaha Keyboard as Midi Controller while also using it's internal sounds, then the sound of the Keyboard is slightly (and noticable) faster than the Sound that Pianoteq produces.

However,  at Pianoteqs  Performance Section, the Audio Load is never above one third of the maximum, and turning the preferences from average to the lowest possible selections (Internal sample rate of 11025 Hz, using 64 samples, and maximum polyphony of 1) doesn't get me rid of the high latency.

What am I doing wrong, and would an external soundcard fix this issue?

Reply by varpa

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Re: Latency Issues despite (appearently?) sufficient processor on linux

An external sound would always be an improvement over the likely low quality built-in sound card.  However, there lots of things to do to optimize performance on a linux machine see: http://wiki.linuxaudio.org/wiki/system_configuration and http://www.libremusicproduction.com/art...arted-jack

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Reply by stamkorg

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Re: Latency Issues despite (appearently?) sufficient processor on linux

varpa wrote:

An external sound would always be an improvement over the likely low quality built-in sound card.  However, there lots of things to do to optimize performance on a linux machine see: http://wiki.linuxaudio.org/wiki/system_configuration and http://www.libremusicproduction.com/art...arted-jack

Quantenirrwisch uses Tango Studio, so the system is optimized for audio.

Do you use Jack?

I recommand you to use jack with this settings:
Priority: 80
Samples: 64 (for a very natural playing experience)
Frequency: 44100 kHz or 48000
Periods: 2

With this settings, the "on the screen" latency should be 2,67 msec in/out

Then you set the max polyphony (in Pianoteq) at 96 or 128.
In these conditions, you should be able to play the keyboard with the right pedal down and increase the polyphony to reach the max without dropouts (Xruns). This situation gives you a very good security.

I can do that with a 2-core Intel 2,53Mhz laptop and with 4Gb RAM.

If you can't, I think the first thing to do is to buy a good external soundcard. If you still have latency problems, then change your pc.

Reply by Quantenirrwisch

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Re: Latency Issues despite (appearently?) sufficient processor on linux

Hi, thanks for the answers.

What use would it have to use Jack, from what I read about it, it operates on Alsa, and will thus only lead to increased latency?

Reply by Mossy

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Re: Latency Issues despite (appearently?) sufficient processor on linux

There's been many threads in the past on tuning Linux for Pianoteq.  If you're not an expert Linux user, you probably will need to read up on all the Linux tricks and tips.  Here are 2 threads with lots of good info:

http://www.forum-pianoteq.com/viewtopic.php?id=3397

http://www.forum-pianoteq.com/viewtopic.php?id=3521

https://soundcloud.com/mossy456/

Reply by GRB

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Re: Latency Issues despite (appearently?) sufficient processor on linux

Quantenirrwisch wrote:

Hi, thanks for the answers.

What use would it have to use Jack, from what I read about it, it operates on Alsa, and will thus only lead to increased latency?

As far as I know Jack replaces Alsa and reduces latency. You probably need to install the special version of Ubuntu that is designed for music processing.  It uses the XFCE desktop rather than Unity. For what it's worth I use Linux Mint, Mate Edition.  While I can't say for your particular computer, Toshibas have a reputation for not working well with Linux, and generally AMD processors are better performers with Linux than Intel. I'm using an Intel Celeron precently and can attest it's not great, but this particular laptop is an Asus distributed by Micro$oft for only $200.00, which included free shipping to Hawaii.  If you live near a Costco, I'd go there and buy one of their lower priced AMD's if they have one, as Costco has a 90 day return policy, no questions asked.  This might sound weird, but it could be a BIOS issue as the one Toshiba I tried and then return had an extremely weird BIOS.

Last edited by GRB (03-01-2015 17:54)
Pianoteq Pro 7.x - Kubuntu Linux 19.10 - Plasma Desktop - Hamburg Steinway

Reply by floyer

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Re: Latency Issues despite (appearently?) sufficient processor on linux

GRB wrote:

As far as I know Jack replaces Alsa and reduces latency.

An interesting page is here : http://jackaudio.org/faq/comparing_jack.html

ALSA: both a HAL and a user-space library for audio under Linux. ALSA is used to provide the default audio i/o driver for JACK. ALSA is a very powerful audio API, but it does not provide a callback-based API or offer any solutions for inter-application communication, though it has been discussed and is theoretically possible.

Then with Jack, ALSA still brings the i/o driver.

Last edited by floyer (03-01-2015 18:58)

Reply by aandrmusic

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Re: Latency Issues despite (appearently?) sufficient processor on linux

The Low latency kernel would probably HELP

If you want a whole lot of other open source music software get UbuntuStudio, currently 14.10.

  http://cdimage.ubuntu.com/ubuntustudio/...0/release/

A 32 Gig partition will hold ALL of this, including lots of graphic arts apps that may be of no interest to many musicians..