+++ This bug was initially created as a clone of Bug #593565 +++ bug 593680 comment 3: > I experience some of this sluggishness although only with D3D, DirectWrite and > D2D enabled (which is by default for my hardware). bug 593565 comment 13: > Adapter Description: Radeon HD 6800 Series > Vendor ID: 1002 > Device ID: 6739 > Adapter RAM: 1024 > Driver Version: 8.782.1.0 > Direct2D Enabled: true > DirectWrite Enabled: true > GPU Accelerated Windows: 1/1 Direct3D 10 > > Disabled hardware accel and tested. With hardware accel disabled opening and > closing blank tabs the animation is far smoother bug 593565 comment 32/33: > I can confirm this. I did a side-by-side comparison in beta 10 with two fresh > profiles, one of which had gfx.direct2d.disabled set to true. Both windows had > a blank tab and I repeatedly opened and closed one or two more blank tabs. > Same with the latest nightly and updated drivers, ATI Radeon HD 4650.

My animations are generally pretty laggy, especially closing. Not even close to as smooth as chrome/opera. http://www.youtube.com/watch?v=oCSJP9nG7Q8 the end half of the video is the best example of the laginess I usually see, at the beginning ti decided to behave just to spite me. win7 64 bit 2GHz core2 duo 4gb ram 512MB Gddr3 mobility hd2600 Adapter Description: Radeon HD 6800 Series Vendor ID: 1002 Device ID: 6739 Adapter RAM: 1024 Driver Version: 8.782.1.0 Direct2D Enabled: true DirectWrite Enabled: true GPU Accelerated Windows: 1/1 Direct3D 10 Disabled hardware accel and tested. With hardware accel disabled opening and closing blank tabs the animation seemed smoother but still occasionally lagged like in the video. It does seem to be worse with d2d enabled though.

Pasted wrong about:support into in previous comment Adapter Description: ATI Mobility Radeon HD 2600 Vendor ID: 1002 Device ID: 9581 Adapter RAM: 512 Adapter Driver: saticfx64 aticfx64 aticfx32 aticfx32 atiumd64 atidxx64 atiumdag atidxx32 atiumdva atiumd6a atitmm64 Driver Version: 8.762.0.0 Driver Date: 8-3-2010 Direct2D Enabled: true DirectWrite Enabled: true (6.1.7600.16699, font cache n/a) WebGL Renderer: Google Inc. -- ANGLE -- OpenGL ES 2.0 (ANGLE 0.0.0.541) GPU Accelerated Windows: 1/1 Direct3D 10 The bug effects the machine in the comment above the same though.

Seeing this as well. Specs, - Radeon 4250M, Athlon II P340 - NV ION, Atom N270

Assigning this to Jeff in case it needs to be reprioritized.