(Already discussed this informally, filing a real bug now that the game is public.) A Space Shooter (http://chrome.aspaceshooter.com) runs well on Linux and OS X but its framerate drags to a halt on Windows. The game uses WebGL. This has been tried on different graphics cards (that otherwise run WebGL code fine). Here is the about:support for one machine: Graphics Adapter Description NVIDIA GeForce GTS 240 Vendor ID 0x10de Device ID 0x0607 Adapter RAM 1024 Adapter Drivers nvd3dumx,nvwgf2umx,nvwgf2umx nvd3dum,nvwgf2um,nvwgf2um Driver Version 8.17.12.7533 Driver Date 5-20-2011 Direct2D Enabled true DirectWrite Enabled true (6.1.7601.17514) ClearType Parameters ClearType parameters not found WebGL Renderer Google Inc. -- ANGLE (NVIDIA GeForce GTS 240) -- OpenGL ES 2.0 (ANGLE 1.0.0.963) GPU Accelerated Windows 1/1 Direct3D 10 AzureBackend direct2d

I should point out that there is a second Mandreel-compiled game that has this performance fault on Win7, so perhaps there is a particular pattern or feature in the code that is disabling optimization. The other game is instrumented to show how much time is spent in the JS render loop and it shows very little time which is why I am initially assuming this is a gfx issue.

This was very likely a hit from our bunch of earlier extreme windows webgl regressions. I can't reproduce on release, and local build is not playing nice with flash, so I can't try to repro there. Worksforme, but can anyone else repro?

WFM also, on the same machine I used to file the bug.