30-way Intel/AMD/NVIDIA Linux 2D Performance Comparison
Intel's SNA acceleration architecture for the Linux desktop is incredibly fast but the size of the implementation is huge and is nearly worked on full-time by an Intel OTC Linux developer (Chris Wilson) while the Radeon and Nouveau driver teams have no one dedicated full-time to Linux 2D performance.
When it comes to the GtkPerf micro-benchmarks, Intel remained in the lead followed by Radeon and then Nouveau.