I'm currently trying to buy a new laptop, and I need one with at least 1.8 GHz of processing power. I've got my eye on the Sony Vaio VGN-TZ21WN/B, but it's "only" got a 1.06 dual core processor. My question is this: does a 1.06 dual core (by some magic) give you an effective processing output of more than 1.06 GHz, and if so, how much more? (If a dual core 1.06GHz is going to be too slow, does anyone know of a laptop under 1.6kg that does have at least 1.8 GHz of processing power?) Any help greatly appreciated.