HD Flash video can sometimes be quite a pain on lower end systems, with the CPU often being choked by the demands placed upon it. Adobe's 10.1 Flash player does include hardware acceleration which uses the GPU but this feature had yet to be made available to OS X users. Finally though, Adobe's Gala version promises to remedy this, but bear in mind this is preview build, so there may be bugs.
labs.adobe.com - Welcome to the Flash Player preview release, code-named “Gala,” which introduces support for H.264 video hardware decoding on Mac OS X 10.6.3, the most recent release of Mac OS X Snow Leopard. Gala allows developers to preview Flash Player with hardware acceleration of H.264 video on supported Mac computers equipped with the following GPUs: NVIDIA GeForce 9400M, GeForce 320M or GeForce GT 330M. The hardware acceleration functionality in the Gala preview release of Flash Player is expected to be included in an update following the release of Flash Player 10.1.
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