Performance issue

Hi,
I am running stepmania on linux on a ZOTAC CI320 Nano machine ( specs: http://www.zotac.com/products/mini-pcs/product/mini-pcs/detail/zbox-ci320-nano/sort/starttime/order/DESC/amount/10/section/specifications.html ) which uses an integrated graphic card ( Bay Trail as it seems to be called ) and I am having wired results.
First the issue I face is that I see framerate drops during songs but I can't really find why.

I initially tried to run stepmania directly on X11 without window manager but it just does not work (someone mentioned a focus issue and I think it's right since stepmania gets no input even from the keyboard), next I tried using i3, a very minimal window manager and it fixed the focus issue.


So Now what I checked/tried !

First I checked that the correct driver was used, it is, I downloaded the official drivers from Intel which mostly included things I have no idea what to do with but there was a small utility which shows the GPU usage when run inside the archive !
Using this tool alongside "top" in another console I launched stepmania to look at the CPU/GPU usage and the results are puzzling...
On the CPU side it is a quad core but it looks like stepmania uses at most 2 maybe 2.5 but none never go further than 70/80% and on the GPU side the usage is even lower so I don't really know where to look at :(

Another srtange thing is that I first tried at 1080p (I forgot to mention the zotac is connected to a TV screen) and then tried 720p but as far as I can tell the framerate drops are the same, the framerate is slighty higher but not by much and it drops in the same way.

Any idea where I could look ?

1) Try Fast Note Rendering in graphics
2) Make sure your color settings are all 32-bit (16-bit is a performance hit on modern systems)
3) Check which audio driver you are using, pulse causes visual stuttering on some systems. SoundDriver=ALSA-sw in Preferences.ini

Thanks for the reply, Fast note rendering was already enabled, colors were set to 16bits so I switched to 32bits but I didn't notice any change :(
I am using alsa for the sound, pulse is not even installed on the machine.

While doing more test I noticed when I have rendering stat enabled in the debug menu that the framerate drop occurs always in sync with a new line shown in the bottom right box (part of the debug overlay) but I can't figure what this box actually shows.

the box shows frame drops. make sure there's nothing else running on the system, too. (chrome, in particular, causes lots of dropped frames for me)

does vsync on/off make any difference for you?

There is nothing else running beside stepmania except for the window manager I had to use.
I tried turning VSync on and off but it does not make any noticeable change :(

That's hard to tell but it may be something linked to the songs themselves, I would have to double check this but I got the impressions that the frame drops always occurs at the same time and a lot more on some songs than others, one of my leads was the animated background but I since found a song with a static picture as background which also suffers from frame drops.

I tried to fiddle with X11 settings for my driver but never manage to see any difference except when disabling 3D rendering which, of course, destroyed the fps for the title screen xD

I was hitting 18 fps with a new Surface Pro 2 factory default settings, couldn't get it any higher no matter the tweaks actually managed about 40fps with the lowest resolution possible. Let the machine install Windows Updates on an 8.1 system and after that it was running at 360+ fps, I Vsynched it and it's a flawless 60fps now. So try system updates, also try changing the resolution of the song with the static BGImage, change it to 640x480 or even 320x240 and see how that affects the FPS.