why dont they have 3.4GHz i7 for laptops?

The fundamental issue this question is stemming from is misconceptions brought on by dishonest marketing all over the world.

Gigahertz means nothing. Don't buy or avoid a processor based on what number they put before "GHz" to describe it. There is so much more that determines processor performance, the clock rate (which is the "gigahertz") is just one tiny aspect of the processor that's overblown for marketing purposes. In reality, a 2.1GHz Core i3-2310M is faster than a 3.06GHz Core 2 Duo (both dual-core).

That aside, processor is probably something that should be far from your main concern. Most computers currently sold come with processors that are far beyond powerful enough for the majority of users.

If you're interested in game performance, the GPU is what you need to focus on as far as performance goes, not the processor. The GPU affects game performance a lot more than the processor. And if you're just a basic user, then you'll be completely unaffected by processor differences.

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http://ark.intel.com/products/52214/Intel-Core-i7-... this tells you why - 95watts power consumption = short battery life and too much heat for a laptop, although this page seems to indicate they do make a low power i7 mobile 3.4 cpu - http://ark.intel.com/products/series/53252 but at $600 it costs more than most low end laptops

Can you have a powerful heatsink/fan inside 1 inch space?

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