C-Ray is one of the benchmarks that does benefit from GCC 4.7 due to general optimizations made within the GNU Compiler Collection.
The Smallpt performance regresses slightly under the newer compiler.
The PostgreSQL database performance is up noticeably on both systems using Ubuntu 13.04 over Ubuntu 12.04.2 LTS.
The Apache web-server performance has dropped slightly with Ubuntu 13.04 on both systems, but this particular Apache test isn't too relevant to most realworld web-serving workloads.
Overall, if you're thinking of moving from Ubuntu 12.04.2 LTS to Ubuntu 13.04 on the basis of better performance, that's true if you're using the open-source Intel/Radeon/Nouveau graphics drivers, the disk performance with EXT4 for a single SSD is mostly unchanged, and for the computational tests it really depends upon the particular workload.
More Ubuntu 13.04 benchmarks are coming with the final release of Canonical's operating system update due out on 25 April.