DonanimHaber has leaked internal benchmarks of Intel's next-gen Sandy Bridge E flagship, revealed to be branded Core i7 3960X earlier this week, put to the test against current flagship Core i7 990X. Both are 6 Core / 12 Thread CPUs fabricated at 32nm. While the i7 3960X actually features a slighty lower clock speed, 0.16 GHz less than the i7 990X, it is based on the improved Sandy Bridge architecture, and boasts of 15MB L3 cache – 3MB more than the 990X. The X79 chipset also supports 4 memory channels – 1 more than X58. Finally, Core i7 3960X features a more aggressive Turbo, clocking all the way up to 3.9 GHz.
Since these are internal benchmarks conducted by Intel, the leaked slides are quick to point out benchmarks influenced by memory bandwidth and AVX instructions (new to the Sandy Bridge architecture). In SPECint_rate the i7 3960X takes a 35% lead over the i7 990X, and a 65% advantage in SPECfp_rate. In Sandra 2011, the i7 3960X nearly doubles i7 990X's performance in Multimedia and Memory Bandwidth tests, once again thanks to 4 memory channels and AVX.
In more relevant real world benchmarks, the picture is less rosy, though not unexpected. In Cinebench 11.5, POV-Ray 3.7 and ProShow Gold 4.5, the Core i7 3960X leads the i7 990X by 12%-15%. The 3DMark 11 is "estimated" at 36%. Judging by these benchmarks, in most multi-threaded applications, we would expect the Core i7 3960X to be about 15% faster than the Core i7 990X. Of course, non-multithreaded applications, applications sensitive to AVX, memory bandwidth and cache will see greater improvements for the Core i7 3960X.
Sandy Bridge-E, alongwith Core i7 3960X, 3930K and the quad-core 3820 are expected to release in late 2011 at the earliest, about one quarter after AMD's FX-Series.