{"action":"created","issue":{"url":"https://api.github.com/repos/servo/webrender/issues/2532","repository_url":"https://api.github.com/repos/servo/webrender","labels_url":"https://api.github.com/repos/servo/webrender/issues/2532/labels{/name}","comments_url":"https://api.github.com/repos/servo/webrender/issues/2532/comments","events_url":"https://api.github.com/repos/servo/webrender/issues/2532/events","html_url":"https://github.com/servo/webrender/issues/2532","id":305734280,"number":2532,"title":"Scrolling simple pages is still slow on my integrated GPU","user":{"login":"mstange","id":961291,"avatar_url":"https://avatars0.githubusercontent.com/u/961291?v=4","gravatar_id":"","url":"https://api.github.com/users/mstange","html_url":"https://github.com/mstange","followers_url":"https://api.github.com/users/mstange/followers","following_url":"https://api.github.com/users/mstange/following{/other_user}","gists_url":"https://api.github.com/users/mstange/gists{/gist_id}","starred_url":"https://api.github.com/users/mstange/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/mstange/subscriptions","organizations_url":"https://api.github.com/users/mstange/orgs","repos_url":"https://api.github.com/users/mstange/repos","events_url":"https://api.github.com/users/mstange/events{/privacy}","received_events_url":"https://api.github.com/users/mstange/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"assignees":[],"milestone":null,"comments":3,"created_at":"2018-03-15T22:00:02Z","updated_at":"2018-03-15T22:38:59Z","closed_at":null,"author_association":"CONTRIBUTOR","body":"I've been using WebRender on my main Firefox profile for a while now, but I've always had to pin my machine to the discrete GPU in order to get acceptable performance. With my integrated GPU, performance is still not good enough.\r\n\r\nFor example, scrolling [this github page](https://github.com/mstange/macos-compositing/blob/master/iosurface-compositing/OpenGLContextView.m#L61-L67) only gets around 30fps. Profile: https://perfht.ml/2tNf5gI\r\nMost of the composite times in the profile are between 25ms and 36ms.\r\n\r\nThe compact profiler overlay shows:\r\nFPS: ~30 fps, Backend: 1.26ms, Compositor: 1.73ms, GPU: 4.52ms.\r\n\r\nI would expect the GPU time to show something higher here, if we end up blocking for 30ms on flushBuffer.\r\n\r\nA big part of the problem is probably the fact that the Window Server considers our window to be transparent, and composites all the other windows underneath Firefox every time it draws the Firefox window. But this is an existing issue that we also have without WebRender, and scrolling with our old OpenGL compositor is noticeably smoother, it gets around 44 fps. (Which is still tragically bad...)\r\n\r\nBut 44fps = 22.7ms per composite. If we assume that non-WebRender creates 0ms of GPU work, and we add WebRender's 4.52ms of GPU work to that, we'd expect composites to take 27.2ms which would be 37fps. But in reality we only get 30fps. So there's still a part of the cost to WebRender that hasn't been accounted for."},"comment":{"url":"https://api.github.com/repos/servo/webrender/issues/comments/373545390","html_url":"https://github.com/servo/webrender/issues/2532#issuecomment-373545390","issue_url":"https://api.github.com/repos/servo/webrender/issues/2532","id":373545390,"user":{"login":"glennw","id":2350882,"avatar_url":"https://avatars0.githubusercontent.com/u/2350882?v=4","gravatar_id":"","url":"https://api.github.com/users/glennw","html_url":"https://github.com/glennw","followers_url":"https://api.github.com/users/glennw/followers","following_url":"https://api.github.com/users/glennw/following{/other_user}","gists_url":"https://api.github.com/users/glennw/gists{/gist_id}","starred_url":"https://api.github.com/users/glennw/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/glennw/subscriptions","organizations_url":"https://api.github.com/users/glennw/orgs","repos_url":"https://api.github.com/users/glennw/repos","events_url":"https://api.github.com/users/glennw/events{/privacy}","received_events_url":"https://api.github.com/users/glennw/received_events","type":"User","site_admin":false},"created_at":"2018-03-15T22:38:59Z","updated_at":"2018-03-15T22:38:59Z","author_association":"MEMBER","body":"<img width=\"1680\" alt=\"mac\" src=\"https://user-images.githubusercontent.com/2350882/37494526-1caf411c-28a1-11e8-8839-f5f8dabb2040.png\">\r\n\r\nThis is what I see on my mac. It *is* an HD630, but I wouldn't expect *that* much difference? On this machine it's easily holding 60 fps. ```about:support``` reports that the Intel GPU is active, and gfx.io says it is running in integrated mode, from what I can tell. Perhaps it's somehow switched to discrete and that's not reported in Gecko?\r\n"}}
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