Linux: Renoise Gui Uses Way Too Much Cpu Under Gnome

I just realized a weird thing when using a XY-Pad: Moving the mouse cursor (while pressing left mouse button) in the XY-Pad is extremely sluggish on my netbook. Actually pretty unusable. Even in an empty, non-playing song.

Then I realized something even weirder: Having an empty, non-playing song opened in Renoise, the Renoise window uses 50% CPU (on both of my hyperthreading cores!). That is, when I open a new song, and minimize the Renoise window, then look at the CPU meter in Ubuntu, it is under 10%, when I now Alt-Tab to show the Renoise window and then do nothing for 10 seconds, and Tab-Alt again to minimize the Renoise window, then I can see in the CPU meter that during these 10 seconds the CPU was constantly above 50%! This is without playing the song or doing anything in Renoise, just the fact the the Renoise window is shown!

What is going on here?

My machine is an ASUS EEEPC 1005HA running Ubuntu 11.10 in 2D mode.

Have you confirmed that is definitely specific to GNOME, e.g. by testing with a different window manager?

I abandoned GNOME in favour of KDE because the GNOME window manager seemed to be interfering with Renoise, although in my case it was causing audio clicks rather than excessive CPU usage. I read somewhere that the GNOME window manager used some realtime “tricks” to get good performance, but I don’t know if that was related to my problem (or yours).

The same happens in Openbox as well.

Opening Renoise, looking at Renoise CPU meter = 9%. Alt-Tab to minimize Renoise, looking at gnome-system-monitor, Renoise = 20%. Alt-Tab to show Renoise again, doing nothing for a while, Alt-Tab again to minimize Renoise and look at gnome-system-monitor, Renoise was above 50% for the time when Renoise was shown and dropped to 20% again, after it was minimized.

Showing Renoise and moving the XY-Pad with the mouse will max out (100%) one CPU core.

Not sure if Renoise supports the recent incarnation of Hyper Threading, I know it didn’t work well with the technology that shared the name on the old P4 processors (really is quite clumsy of Intel using the same term twice!) I know I have read people recommending disabling it but then I think they may be confused with the old technology. Might be worth doing some tests though…

Also have you tried the GUI options in Preferences? Try turning off Effects and Animations and toggling the More Compatible Graphics option (if it exists on Linux.)

Yes, switching effects off does not help. I also tried setting the GUI rate to 60.

Hyperthreading is not the problem here, as the CPU increases on both cores.

This does more or less also apply to Linux:

  • there are some other XWindows related issues that definitely could/should be improved…

That said, Renoise is not really optimized for netbooks. It gives timing (see linked thread above) more priority than being gentle to the CPU. I think that’s in overall a fair compromise. And such a GUI usage never affects audio timing and stuff which is what’s most important for an application like Renoise.

Thanks for the link taktik. However, I do understand the high idle CPU usage for pumping midi in realtime (20% on my system). The part that confuses me its that showing the Renoise GUI will add another 30%!
This combined with the fact that merely moving the cursor in the xy-pad will max out the CPU, makes me wonder, why the GUI (not other aspects of Renoise) uses such a huge amount of processing.

in my experience ubuntu is a whore with resources. especially with a netbook with an atom processor. having been around the block with lowend hardware trying every distro under the sun, my advice is get yourself a lightweight distro thats not ubuntu. i really like antix for lightweight. theres also crunchbang, linux mint debian xfce, and if you really want to stick with buntu, try lubuntu.

i really think this is an ubuntu problem

^ may i suggest Crunchbang Linux? it is awesome and very light and has an absolutely wonderful community.

I doubt it. I don’t see what Ubuntu could add here that leads to GUI problems (keep in mind that I tested already with Openbox, too rule out Unity as the source of the problem).

But I will be happy to test with Arch at some point, too.

@fladd: i tend to agree with you, seeing how you tested with elimination of the most resource-hungry component of the OS, the window manager. however, this does not completely rule out that it is a Ubuntu-problem (although i doubt it). Ubuntu is a very specific Linux distro, with lots of specific packages etc, some of which have come a long way from Debian Stable. this kinda goes for all the different distros, and have heard many people say ‘my such-and-such-card didn’t work on whatever distro i tried, but it worked on this one!’, and the exact reasons to that are unclear. so it couldn’t hurt trying this out on a different distro.

I just started using Ubuntu at work. 10.04 LTS, mind you.

It’s not related to Renoise but I have a 100% CPU bug that I can reproduce using Gnome/Openbox every single time. Posted here:

Just emphasing that, yes, Ubuntu can cause random shit.

I just tried duplicating what you wrote and I can’t get more than 15% in Renoise. Not a Netbook, mind you.

It would be really helpful to the thread if someone else can confirm “100% CPU” usage on their Linux rigs.


Not really helpfull, but personnaly I’m using (after dozens of tests of other distributions and configurations) Tango Studio, a low latency distribution based on Ubuntu 10.04 LTS, with low latency kernel and all the audio stuff pre-installed (Jack, etc…). I never had this cpu behaviour under my setup, even if the distribution is using Gnome as standard desktop manager.

Are you saying:
A) I do not get the same behaviour, Renoise uses always 15% with and without GUI,

or are you saying:
B) I do get the same behaviour and observe an increase of 15% when the GUI is shown, compared to when no GUI is shown?

I do not get the same behaviour. Renoise open, doing nothing, is 0% CPU.

Renoise, jiggling the X/Y, clicking stuff, trying hard to get 100% CPU, is max 15% CPU.

And so on.

I’m using “System Monitor 2.28.0”

Have you considered that it’s a graphics driver issue? I’m using the proprietary drivers provided by NVIDA, for example.

I’m no Linux expert. What I propose is other Linux users confirm the behaviour. If it’s not reproducible…


Yes, it could be graphics driver related. But still, it only happens with the Renoise GUI, not with any other programme!
Except Renoise uses some graphics stuff that other programmes like Firefox etc. do not use (like OpenGL or something).
My graphics card is an Intel Integrated 945GME.

OK so here are the results of my tests

Slackware 13.37:
Renoise minimized 0-5%
Renoise maximized 2-8%
Renoise maximized playing with XY pad 12-30%

Windows 7:
Renoise minimized 0-1%
Renoise maximized 1-10% (increasing to 10 when mouse is moved erratically across interface)
Renoise maximized playing with XY pad 15-22%
Renoise maximized playing with a slider 12-17%

This is with an Acer Aspire 5253-bz602, which has the AMD Dual-Core E-350 processor, which is a fairly modern “Low Power Mobile” Processor.

[s]I notice you said when playing with the xy pad you get 100% of one core. You are mistaken here because your processor is single core, but with 2 threads. So the OS reads it as 2 cores. So really its using 50% of your single core processor. In linux, when playing with the XY pad, all processes combined including X and renoise, I’m at about 64% of one core on my Dual-Core processor, and renoise is claiming about 30% (so total 32% and 15%, respectively). Thats on a full size laptop which is definitely faster than the atom processor in your netbook. There is a definite but minor cpu usage when a single slider is being moved (12-17% cpu), then factor in you are controlling 2 sliders at once when playing with the XY pad, it make sense how much cpu is being used. I mean 100% of one thread for you is 50% overall so its not like its maxing out.

I think the main issue here is the hardware you are using. Want less CPU usage? ditch the netbook, which is intended mostly as an internet and email pc anyway, not a music production system. I know its convenient and portable and all but a single core 1.66 ghz processor is not going to give you what you need for audio production.[/s]
{edit: i stand corrected, hardware was not the issue!)

PS I never use the XY pad

Anyways good luck!

@fladd, if you really think that this is a gui related issue, you could give a try to to get more insight into, what’s going on on your x server.

The point here is not that my netbook is not capable of entirely producing the next justin timberlake single, the point is that moving one specific element of the gui will lead to a complete overload! (And yes, I know that there is only one phyiscal core in my atom chip…) The renoise gui gets non-responsive and the xy-pad “jumps” like in Windows when it is at 99% and you try to move a window, it will move, but you will only see it jump in large steps to the position you move it to. The same happens in Renoise with the XY pad. I move it, but when I move it from left to right to left again, I don’t see this as a smooth movement, but I see two intermediate positions of this movements, As if the gui is updated at 1 hz as soon as the curser is captured in the xy-pad.

This is as good as I can describe the problem. As I mentioned before, I will test on Arch as well.
Thanks for your testing!