Against http://hg.mozilla.org/mozilla-central/rev/264f0a7a878c (x86) with D2D and D3D10 on I get ~20 fps with an AMD 4850 on Win 7. Compared to e.g. Chrome Canary where I get ~50 fps. Cleopatra Profile against http://hg.mozilla.org/projects/profiling/rev/4f05b58b9925 (x86): http://people.mozilla.com/~bgirard/cleopatra/?report=AMIfv95tJ_OW2fcBRutioR70X42BzfM1A_t7mOgiYeyoFFqDXSj_JWoNf0QQQucJb6mhgPZonT8AcjBo0c_y1W22OQ0QGQ4BaR2X4RaPjA9k7sAV2cSbKjBMnuGn4ntDqFP4MpHr9rkubF-zEuFAz6qxmtsSIRF7og Large Time spent in GFX, rather small Part in JS (if I read the Profile correctly :-)).

Firefox Nightly (20120621053048) ~30fps Opera Next 12 build 1473 ~42fps Internet Explorer 9 ~55fps Chrome Canary (22.0.1182.0) ~55fps Win7 x64, PhenomII x6 1090T, 4GB DDR2-800 Graphics Adapter Description = NVIDIA GeForce GT 240 Vendor ID = 0x10de Device ID = 0x0ca3 Adapter RAM = 1024 Adapter Drivers = nvd3dumx,nvwgf2umx,nvwgf2umx nvd3dum,nvwgf2um,nvwgf2um Driver Version = 9.18.13.448 Driver Date = 6-11-2012 Direct2D Enabled = true DirectWrite Enabled = true (6.1.7601.17789) ClearType Parameters = ClearType parameters not found WebGL Renderer = Google Inc. -- ANGLE (NVIDIA GeForce GT 240) -- OpenGL ES 2.0 (ANGLE 1.0.0.1041) GPU Accelerated Windows = 1/1 Direct3D 10 AzureBackend = direct2d