When it comes to audio encoding, the applications we're testing don't seem to make good use of more than two CPU cores. The dual-core Phenom II X2 555 overclocked to 4 GHz meets or beats Core i5-750 performance, but when all of its four cores are enabled and the clock speed is reduced to 3.8 GHz, the AMD CPU loses ground. The Pentium G6950's high clock rate wins the day easily here.
Video encoding performance is greatly dependent on the codec used. Xvid and MainConcept H.264 show the best results with the overclocked Phenom II X4 555 running four cores, as expected, but DivX prefers raw clock speed, and the overclocked Pentium G6950 takes the win.
3ds Max has always made use of extra CPU cores, so the quad-core Core i5-750 and core-unlocked Phenom II X2 555 easily take this benchmark. But 3ds Max also appears to have an affinity for the Clarkdale and Lynnfield designs. Notice that the 3.8 GHz quad-core Phenom can only meet the performance of the 2.66 GHz Core i5-750. Even the 2.8 GHz Pentium G6950 beats the dual-core 3.2 GHz Phenom II X2 555. The overclocked Pentium puts up a good fight, but can't reach the quad-core numbers.
Photoshop performance seems to be dominated by the Intel CPUs, but the core-unlocked Phenom II X2 555 manages a tie against the stock-speed Core i5-750 here. The dual-core Phenom II X2 555 struggles to keep up with stock Pentium G6950 performance, even when overclocked to 4 GHz.
WinRAR is able to utilize available execution resources, while WinZip, which is not threaded, scales according to clock rate. It is strange that the program hits a performance wall at about four and a half minutes. Perhaps we're seeing an I/O bottleneck here.