Primus is a shared library that provides OpenGL and GLX APIs and implements low-overhead local-only client-side OpenGL offloading via GLX forking, similar to VirtualGL. It intercepts GLX calls and redirects GL rendering to a secondary X display, presumably driven by a faster GPU. On swapping buffers, rendered contents are read back using a PBO and copied onto the drawable it was supposed to be rendered on in the first place. For more information, refer to [technotes.md] (https://github.com/amonakov/primus/blob/master/technotes.md).
To use, install or build from source and use primusrun
wrapper script.
primus-9999.ebuild
in the bumblebee
overlayLIBDIR=lib make && CXX=g++\ -m32 LIBDIR=lib32 make
Adjust LIBDIR
variables above as appropriate for your distribution
(reflecting how /usr/lib*
are named):
lib
and lib32
as abovelib64
and lib32
lib64
and lib
lib/x86_64-linux-gnu
and lib/i386-linux-gnu
Ubuntu (with multiarch) seems rather inconsistent. The dynamic linker
expands $LIB
to x86_64-linux-gnu
/i386-linux-gnu
(without lib/
), but
Nvidia drivers are installed into /usr/lib{,32}/nvidia-current
. Something
like the following is needed:
export PRIMUS_libGLd='/usr/lib/$$LIB/mesa/libGL.so.1'
LIBDIR=x86_64-linux-gnu make
LIBDIR=i386-linux-gnu CXX=g++\ -m32 make
unset PRIMUS_libGLd
Starting from 13.04, Ubuntu needs the same LIBDIR
paths as Debian (with
leading lib/
); consequently, lib/
in PRIMUS_libGLd
should be omitted.
Furthermore, libnvidia-tls.so
is not present in default shared library
search directories. Uncomment the corresponding line in primusrun
.
Since compositing hurts performance, invoking primus when a compositing WM is active is not recommended. If you need to use primus with compositing and see flickering or bad performance, synchronizing primus' display thread with the application's rendering thread may help (can anyone investigate why?):
PRIMUS_SYNC=1 primusrun ...
This makes primus display the previously rendered frame. Alternatively,
with PRIMUS_SYNC=2
primus will display the latest rendered frame, trading
frame rate for reduced visual latency.
Q: Performance does not exceed 60 fps, I was getting more with optirun/VirtualGL.
A: This is the effect of vblank synchronisation. For benchmarking, you can use
vblank_mode=0 primusrun ...
, but in practice this will probably only waste power,
as your LCD panel does not display more than 60 frames per second anyway.