Q: id like to know in order which is best ... thx
A: The Pentium D (dual core version of the Pentium 4) is a desktop processor that should never go in a laptop (I don't think any did, though some P4's sadly did make it into laptops (which then developed a reputation for overheating)). Right now the Core 2 Duo is the best you can get for laptops (the Core 2 Extreme for laptops is just a highly clocked Core 2 Duo with a high price tag and not much extra performance) with there being no laptop quad core (i.e. the Core 2 Quad does not exist in laptop world). Of the current ones the order is: Pentium Dual Core and Turion X2 tied (both low end products) Core Duo quite a bit faster per clock Core 2 Duo even faster per clock With power consumption roughly the same (the Turion and Core 2 are both 64 bit). There is also the Core Solo used in ultraportables which only has one core and so is slow but doesn't use much power or generate much heat.