Cheers Matt funnily enough was looking at that new i3 one that could be the one.
What's sandy bridge? Seems awful stupid to put sand in a pc !
Sorry, didn't notice this, Sandy Bridge is the newest CPU core. To put it in simple terms, it's about 15 - 20% more powerful than the previous Nehalem core. It also has a host of other improvements, with integrated graphics that actually surpass the performance of low-end dedicated graphics, and they run much cooler, have improved hyperthreading, and have improved energy usage (use less electric).
A regular i3 on the Sandy Bridge core, at stock, tends to be able to keep up with a regular i5 on the Nehalem core (of course there's a lot more variables to consider, such as clock speed, number of cores, chipset etc... but just a general idea), or at worst, give them a good run for their money.
Ivy Bridge is out in April, which will replace it, and looks like another huge improvement, but if you wait for that, prices will be higher and it's just a never ending story. Prices of Sandy Bridge CPU's have been bottoming out recently, due to the upcoming replacement, so now is good time to grab a bargain (plus being so close after Xmas).
From what you're intending to use it for, a lowish Core2Duo would probably suffice, so an i3 Sandy Bridge would be plentiful. The i3 may be seen as the lower spec, but it's actually considered mid-high end in the grand scheme of things (Core is Intels flagship brand), behind the i5 and i7, but with the Atom/ULV's, Celeron and Pentium all being below it in the pecking order. Tis every bit as powerful as a comparable i5 in most situations, aside from a couple of features missing (turbo mode etc), that the average user probably won't have a clue about or notice. It also get a little more complicated, in that Core CPU's with 2xxx are based on the newer Sandy Bridge core, and offer, as above, a significant improvement over the original Core i3/i5/i7 CPU's.http://www.cpubenchmark.net/cpu_lookup.php?cpu=Intel+Core+i3-2120+%40+3.30GHz
This is a "very" crude way of benchmarking, but it gives you an idea at least, of the performance. Compare it to what you have now for a loose idea of the performance gain.