Is 1.6GHz in an i7 quad core enough?

It is an i7 - it is quite capable with its multi threading (it has 8 thread capability). If you are on a budget, go for it. If you can afford more, I'd go for a higher end i7 chip, just to future proof your investment.

Your i7 1.6 ghz can be overclocked to approx 2.7 ghz, which is higher than your stock i7 940 processor running at factory frequency. Have a read about overclocking before you try it though - although I am not sure if laptops provide overclocking capability.

If they do, you just might have a budget version of an i7 that can stand up to the big boys provided it is set correctly and has adequate cooling. But the reality is, 8 threads no small matter (a thread is the smallest unit that can be processed). i7 is named that way because we computer nerds alwas label the first of a series as 0. The i7 can be looked at as processing 8 units at a time as compared to earlier chips - albeit at a smaller frequency in the case of the 1.6 ghz.

As you mentioned, if you are gaming, a video card will help out quite a bit. Have you thought about a desktop with a more beefy i7 unit and a multi graphic card layout (Crossfire X or SLI)? It is relatively cheaper, and way more upgradeable in terms of constant changes. You may want to do a search for what I just typed regarding CrossfireX and SLI - I am too lazy to explain; sorry ;)

Good luck and enjoy your gaming! I know I do!

Well the Intel i7 1.60GHz is most likely an i7-720QM (am i right) which has a turbo boost to 2.80GHz (This is not overclocking, it is a turbo boost frequency built into the Processor itself to increase the performance which the latest Intel i3, i5 and i7 Processors provide. If you try and overclock a normal laptop Processor you will more than likely destroy it lol) so it is a great Processor more than capable to play any game, also it has 4 Cores which is much better than most Processor's with only 2. If it is the i7-720QM then this is the 11th best Laptop Processor you can buy today! Let me tell you that is pretty damn good lol

The Radeon HD5870 is a great Graphics Card and with that Processor you will be able to play ANY game on High to Max settings (even Crysis lol) It will BLITZ FSX!

Baring in mind you have at least 4GB RAM your good to go.

First of all, search online for how high you can overclock it. But 1.6 Ghz will be relatively good, but it will affect the graphics somewhat. That is because the computer will automatically see that the speed is slower, so it might disable alpha effects,or any other other important things (3D, Hexing, and many other things). So if you can get it overclocked to anything over 2 Ghz, you will be fine.