HardMac reports that Polish website PCLab prematurely leaked performance numbers on Intel's upcoming Xeon Gulftown (Core i9). The results have since been pulled but is summarized by HardMac:
First figures indicate that this CPU is very promising. At equivalent clock speed, it is 50% faster than the corresponding quad core Xeon for parallel tasks. Despite having 50% more transistors, the CPU strongly benefits from 32-nm engraving as it drains 50% less power in idle mode and 10% less in full loading mode.
According to their sources, Apple is planning on using the Gulftown processor in a future Mac Pro revision due in early 2010. When placed in a dual-processor configuration, this would give the Mac Pro 12 physical and 24 logical cores. Such massively multi-core designs have been expected for some time with under-the-hood changes in Snow Leopard specifically preparing for such a possibility.
The use of the high-end Gulftown processor in the Mac Pros make more sense now that we've seen Apple using the Core i7 processors in the iMacs. Benchmarks have shown that the performance of these high-end iMac rivals that of the entry level Mac Pros which cost considerably more. The use of Gulftown would presumably reestablish a larger performance gap between Apple's consumer and professional desktop computers.