WPF Performance Fix for Windows Vista and XP
Microsoft released a hotfix a few days ago that is fixing a problem that affected some Windows Vista and Windows XP systems. the knowledge base articles Performance for a WPF-based program that uses the layered windows feature may be less than expected in Windows Vista and Performance is poor in a WPF-based application in which you have enabled layered windows in Windows XP or in Windows Server 2003 are unfortunately offering only a mediocre explanation.
My understanding is that the hotfix fixes a problem with .net applications that see high CPU usage, low framerates or jittery animations among other symptoms. The hotfix addresses the Layered Window performance. In Windows Vista the the hotfix improves the read-back of video memory to system memory while layered Windows were rendered in software emulation in Windows XP which will now use hardware acceleration to improve performance.
The hotfixes can be downloaded from Microsoft directly and require a genuine system. Click to download the hotfix for Windows Vista or Windows XP. Users who did not experience difficulties yet are asked to wait until the Service Pack 1 for Vista and the Service Pack 3 for Windows XP are released. The Service Packs will contain the hotfix.