System tests
For compression tests (WinRAR and FFMPEG), the Pirates of the Carribean 2 HD trailer was used. Track 19 from the Linkin Park Reanimated album was used to benchmark LameEnc.
WinRAR
FFMPEG
LameEnc
Adobe Photoshop CS2
The Driver Heaven Photoshop CS2 benchmark was used to obtain results.
In all the system tests we ran, with the exception of LameEnc (perhaps our file wasn't big enough for any large difference to be noted), quad core is faster than its dual core counterpart. If this difference is big enough, that is up to you to decide. I'm sure that if you use your PC to encode video daily, or you work with large amounts of data that need converting to some form or another, you will be grateful for every second or minute you can shave off. On the other hand, if you just encode video that you gather from your holiday trip once in a while, this time difference is not great enough to justify the purchase of a quad-core cpu.