User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:22.0) Gecko/20130322 Firefox/22.0 Build ID: 20130322031028 Steps to reproduce: Visit the http://www.battlefield.com/battlefield-4 site for the reveal of Battlefield 4. They have an interesting background which is a window above an image, the user swipes the cursor across the page to reveal whats behind, for the condensation to return after a time… The animation isn’t as smooth as it could be, with Chromium 25 performing better. Need to investigate if this is a Firefox issue or how they have coded the behaviour to prefer webkit/v8.
Created attachment 729623 [details] ‘minimal’ testcase Site is closing soon, so keep a pared* down version as a test case. Depends on jQuery from googleapis.com and two images on battlefield.com *for whatever minimal is accepted, HTML is bare-bones, JS is scarily wasteful but likely a chunk of the perf issue.
Captured a profile of this http://people.mozilla.com/~bgirard/cleopatra/#report=717064f260fbad4fc62c5aef51e543ff9551ea91 lulls in graph is where I am pausing the mouse cursor for a few seconds to allow the swipe to fade and just to make the sampling clearer. Is this capturing useful info?
Mixed content blocking breaks this testcase... do you know if this is still an issue?
On the most recent Nightly, yes, it still has jank. https://github.com/johndrinkwater/battlefield-test-case should have all the files to run locally
I can't reproduce using 64-linux-nightly
Still there for me in Nightly 2013-08-26; Chrome still performs better in responsiveness and smoothness of drawing. Tried with OMTC about:config flags which improves the smoothness of animation and doesnt have the sudden pauses but latency is much worse - mouse cursor can be ahead by ~100 pixels Adapter Description NVIDIA Corporation -- GeForce GT 630/PCIe/SSE2 Device ID GeForce GT 630/PCIe/SSE2 Driver Version 4.3.0 NVIDIA 325.08 GPU Accelerated Windows 0/1 Basic windowLayerManagerRemote false AzureCanvasBackend cairo AzureContentBackend none AzureFallbackCanvasBackend none AzureSkiaAccelerated 0