hola,
mostrar la diferencia entre las dos:

[tutua@tutua-pc ~]$ sudo glxspheres64
[sudo] password for tutua:
Polygons in scene: 62464 (61 spheres * 1024 polys/spheres)
Visual ID of window: 0xd2
Context is Direct
OpenGL Renderer: Mesa DRI Intel(R) Haswell Mobile
62.116156 frames/sec - 53.454679 Mpixels/sec
59.998355 frames/sec - 51.632184 Mpixels/sec
59.972468 frames/sec - 51.609907 Mpixels/sec
60.047678 frames/sec - 51.674630 Mpixels/sec
59.945947 frames/sec - 51.587084 Mpixels/sec
[tutua@tutua-pc ~]$ sudo optirun glxspheres64
Polygons in scene: 62464 (61 spheres * 1024 polys/spheres)
Visual ID of window: 0x20
Context is Direct
OpenGL Renderer: GeForce 940M/PCIe/SSE2
136.174086 frames/sec - 117.185971 Mpixels/sec
132.995848 frames/sec - 114.450907 Mpixels/sec
132.995783 frames/sec - 114.450851 Mpixels/sec
135.092802 frames/sec - 116.255462 Mpixels/sec
132.695272 frames/sec - 114.192243 Mpixels/sec
131.583225 frames/sec - 113.235260 Mpixels/sec
[tutua@tutua-pc ~]$
salu2