I want to buy a new ultrabook. But I am confused due to less clock speed of ultrabooks. Even a basic laptop of 2nd gen intel processor has clock speed more than 2GHz. But most of the ultrabooks are having clock speed less than 2GHz. Why is it so?
Depends if its the same architecture underneath. If thats the same, then yes, it will affect performance negatively.
If gaming performance is what you are after, would be looking at a different laptop. Ultrabooks from what I can tell are geared toward more office and general usage, not really gaming.
no gaming is not the main requirement. I want a portable and fast laptop. So i chose the ultrabook. But i do want to play games on it, particularly games like nfs. I m not a hardcore gamer but not a casual too. For example some games require at least xyzGHz processor. And if my ultrabook doesnt have that much then i will not be able to play that game. I m not talking about very high end games.
Well the portable and fast aspect is true, they are pretty small and use SSD's, so they are pretty fast.
But as I said, gaming will not be their strongpoint. I suspect you will get decent performance from one (~HD3000 integrated graphics level).
EDIT: For better gaming performance, look at the ones that have HD4000 integrated, or even better a dedicated GPU. You can see which ones have what under the Chief River selection. http://en.wikipedia.org/wiki/Ultrabook
An Ultrabook is the exact opposite of a gaming laptop... No Ultrabook will be half decent at playing games. They are clocked down because of temperature (small enclosure) and to conserve battery.
You will however be able to play pokemon, on a GBA emulator =) Modern games at decent FPS and settings.... No
BTW the hd 4000 gpu is also clocked down, so no point in seeing desktop benchmarks with it, about half the core clock, bue varies with brands.