User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.1pre) Gecko/20090620 Shiretoko/3.5pre Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.1pre) Gecko/20090620 Shiretoko/3.5pre In the URL I provided, the scrolling background effect is laggy and doesn't scroll smoothly and it uses 100% of 1 CPU core (not really the problem). IE 8 - 100% of 1 CPU core and it scrolls worse then Firefox 3.5pre Chrome 3.x - 100% of 1 CPU core but it scrolls smoothly and looks nice. Reproducible: Always Steps to Reproduce: See details. Actual Results: See details. Expected Results: See details.
Even with D2D/DW enabled on the latest 3.7a4pre nightly build, I'm still seeing this using 100% of 1 core on my i7-920 (overclocked to 4ghz). Also have an HD5870 with the latest 10.3b drivers installed.
Unfortunately the testcase has disappeared. However, we should have improved the performance of things with fixed-position backgrounds significantly via layers. Please reopen this bug if you've got a working testcase.