Laptop Questions

[Guy Davidson]

I'm moving out of the US for a few years in a couple of months, and I want to buy a laptop before I leave. I figure that makes for a good gift for myself, and something that is much cheaper here than it is where I'm moving to (Israel). I haven't bought a new computer in about two years, and I'm trying to figure out what's worth my money and what not. I will mainly be using this laptop for internet, music, and word processing, although I do plan to watch movies and game on it too (not talking about running Crysis with all the settings pumped up, but the occasional RTS or RPG with decent graphics and a good frame rate). Your advice would be very much appreciated with the following:

Is there any underlying difference between (for example) Dell's Inspiron and XPS series, other than the available configurations for each one?

I'm thinking about getting a 15.4" laptop, for a reasonable combination for portability and a nice sized screen. Is there any good reason to consider getting a different size?

Where do the diminishing returns on the processor start? Is it worth moving from a T5500 (2MB cache/1.83GHz/667Mhz FSB) to a T7500 (2.2GHz/800Mhz FSB, 4MB Cache) or T8300 (2.4GHz/800Mhz FSB, 3MB Cache)? Is it worth going even further, and upgrading to a T9300 (2.5GHz/800Mhz FSB, 6MB Cache)? If not, out of the 8300 and 7500, which are the same price, which is superior in performance (I hear the 8300 is better, but I'm not sure)?

Is it worth going beyond 3GB of ram, to 4GB? Or would 3 be enough?

Is there a significant enough performance difference between a 7200rpm and a 5400rpm to justify moving up? Or would a 5400rpm hard drive be fast enough?

With dedicated graphics cards, where do they start showing a significant increase over performance over integrated? an NVIDIA 8400GS? 8400GT? 8600GT?

Is there a good reason to spend extra for a wireless card with 802.11n support?

Is it worth getting the bigger battery (for example, 9-cell over 6-cell)? Or would I be better off spending that same money buying a second battery, for example?

Anything else I didn't ask and should really know or think about? Is it worth spending to get Vista Ultimate over Home Premium? Any laptop brands you recommend or ones you suggest staying away from?

Thank you very much.