French Developer Reports Significant Speed Bump Under Snow Leopard
Christophe Ducommun, the developer of video software MovieGate
has found, as reported by the French website HardMac
, that he was able to go from 104 frames per second encoding under Leopard to 150 frames per second under Snow Leopard making use of Grand Central Dispatch and OpenCL, two new technologies used in the current release.
Grand Central Dispatch is a way to more efficiently make use of multiple-core processors. Ordinarily, a programmer would have to write explicit code for dual-core and quad-core CPUs, but GCD handles this for the developer. OpenCL allows programs to take advantage of the video card's graphics processing unit (GPU), normally used for rendering, to share the load with the CPU.
In addition, Ducommun found that MPEG-2 encoding went from 100% to 130% CPU utilization on a quad-core Mac Pro - showing GCD taking advantage of his multi-core CPU - and decoding dropped CPU utilization from 165% to 70%, which indicated that the work had been offloaded to the GPU.
This is one of the first examples of a developer realizing significant performance improvements merely by turning on support for an existing feature in Snow Leopard. We should see more such news in the weeks and months to come.