Get the trial of WinRar. That is SMP and will take advantage of both your cores.
As Carnage said you have a early Dual Core system. SMP (Symmetrical Multi Processing) is the term used for programs that can use both cores when doing actions. 7Zip is not a SMP program. WinRar is.
As Carnage said you have a early Dual Core system. SMP (Symmetrical Multi Processing) is the term used for programs that can use both cores when doing actions. 7Zip is not a SMP program. WinRar is.