Sandy Bridge New Acceleration (SNA) has had an interesting history over the past year and while it's not yet turned on by default, it's performing very well. While the name implies it is for "Sandy Bridge", the 2D acceleration architecture has support for pre- and post- Sandy Bridge Intel graphics processors.
Chris Wilson of Intel's Open-Source Technology Center shared some new Cairo benchmarks on his personal blog of using an Intel 855GM with a Pentium III mobile processor. The results are surprisingly positive for SNA and better than the default UXA. This is good news should you unfortunately be stuck with this very old second-generation Intel integrated graphics processor.
For those using the more pleasant Sandy Bridge hardware, a few weeks back I posted benchmarks comparing SNA vs. UXA vs. GLAMOR. Coming up soon will be the same comparison but with the latest-generation Ivy Bridge graphics.