Canonical's Scott James Remnant recently set out to explore why X.Org started up so much faster on Moblin than on Ubuntu (particularly, the latest 9.04 development code). On an Atom-based netbook (the Dell Mini 9) he found it took Ubuntu's X Server about four seconds to start before the session manager was called. With Moblin on the same hardware it took just about a second and a half.
Scott began analyzing the X Server patch-set for Moblin, that included enabling UXA acceleration by default, avoiding duplicated saved hardware states, reducing the driver boot-time, and disabling other operations. However, Ubuntu already incorporated all of these patches besides using UXA acceleration. Ubuntu's X Server also has a few extra patches, but those didn't seem to impact the performance.
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