These two applications clearly differ when it comes to support for threading, with iTunes barely differentiating between processors. Conversely, HandBrake clearly utilizes multiple threads, showing an advantage to the Phenom II X6 1075T over Intel's Hyper-Threaded Core i7-920.
The Core i5-750 shows an advantage over the Core i7-920 in iTunes. This is one of those artifacts of threading versus raw clock rate. The Core i5-750 enjoys a higher maximum Turbo Boost frequency than the Core i7-920, allowing it to hit higher frequencies in single-threaded workloads like this one. Were iTunes optimized to run across four cores, the Core i7 would have undoubtedly established a lead.
When it comes to video encoding, TMPGEnc’s DivX and MainConcept’s H.264 encoders take good advantage of the Phenom II X6’s extra processing cores, while TMPGEnc’s Xvid encoder performs faster on the Intel models.
As far as 2D and 3D graphics are concerned, multiple cores are a necessity. 3ds Max even shows a small advantage in favor of the Phenom II X6’s extra processing cores. But it also appreciates the Hyper-Threading capabilities of Intel's Core i7-920.
Photoshop demonstrates a definite performance advantage when run on Intel processors compared to AMD’s similarly priced counterparts, although the Phenom II X6 does place well here.
AVG shows it can use more than two CPU cores, but aside from that, it doesn’t seem to make a difference whether clock speeds or architecture changes.
WinRAR definitely performs better on the high-end Intel processors. The Pentium G6950 is bested by the Phenom II X2 560. 7-Zip appears to take better advantage of multiple threads, and the Phenom II X6 1075T edges out a slight win here.