How to compare intel dual core vs intel core 2 duo

If you are using the system for the basic computing tasks that you list, don't worry about it. Just buy the fastest, cheapest thing you can find.

Having said that, the second generation Wolfdale cores are, clock for clock, a little faster than the 65 nm Conroes.

I have a Wolfdale based 2.93 GHz E6500 in a G'byte G41 motherboard doing basic computing tasks. It hardly ever drops out of SpeedStep.

What is speedstep ?

SpeedStep is Intel's power saving feature on all of their processors. It allows the CPU to downclock itself to be more power efficient. Basically, as long as you keep the CPU load under a certain threshold, it will run at a lower frequency. When you put it under load, SpeedStep clocks it back to 100% to give you the umph you need.