mesa-demos/subtexrate low rate

Output of “vblank_mode=0 /usr/lib64/mesa-demos/tests/subtexrate”:

ATTENTION: default value of option vblank_mode overridden by environment.
ATTENTION: default value of option vblank_mode overridden by environment.
ATTENTION: option value of option vblank_mode ignored.
GL_RENDERER: Mesa DRI Intel(R) Sandybridge Mobile 
glTexSubImage: 512 x 512, 4 Bpp:
   223 calls in 5.02 = 44.47 calls/sec, 44.47 MB/s
glTexSubImage: 256 x 256, 4 Bpp:
   928 calls in 5.01 = 185.16 calls/sec, 46.29 MB/s
glCopyTexSubImage: 512 x 512, 4 Bpp:
   3483 calls in 5.00 = 696.60 calls/sec, 696.60 MB/s
glCopyTexSubImage: 256 x 256, 4 Bpp:
   14328 calls in 5.00 = 2865.60 calls/sec, 716.40 MB/s
exiting

I’ve been told glTexSubImage is supposed to be way higher.
https://github.com/amonakov/primus/issues/96

I’d suggest you post on the mesa mailing list (mesa-users Info Page) and see what sort of bug report you should file.