its not about running single application.. i haven't played a game on my Core 2 Quad.. but overall resposiveness and multitasking is a lot better on Core 2 Quad.. window switching is so much easier and smoother in Core 2 quad that even if u have dozenn windows of different application runing than u don't have to go around closing all of them before opening Photoshop or maltab.

Thats a wrong notation that core 2 quad doesn't increase performance on a single application so no need. u don't have to worry if virus scan initiate while u r playing the game.. other core will take care of it..

These benchmark although give a good estimate of certain applications under isolation but they fail to show the benefits or disadvantages in daily usage scanerios.

Single at 3.4ghz Celeron

My mates is 8 cores at 2.66ghz each

Pentium 4 Prescott @ 3ghz so 1 core hyper threaded

that is a bit much for that, i do alot video and high end graphics, so its a bit necessary and the tower is showing its age now, im expecting to be forced to upgrade based on software requirements.

on a side note, does this teacher go by brother dave by any chance, i had a math teacher back in the day who was a computer junkie, and that seems lie something he might do 

single amd athlon xp 2500+

Intel Quad Core Q9550 2.83ghz

Overclock that baby. I bet you could get it up to 3.83ghz.

Quad Core QX6600 laptop 2,8 ghz

Dual Core 2.8GHz

I have a dual core laptop with 3GB of RAM, a GeForce 8600M screendriver and a 640GB hard drive... that overheats and starts lagging when I play absolutely anything on it. Never buying the cheapest machine for a set of specs that I can find ever again. ^^