Quote: "So for a programmer guy who doesn't mind having 3-4 hours battery life, would you recommend the P4 3.06GHz"
In your dreams. Point out a P4 with that much battery life and I'll point to one thats either off, or has a small nuclear power station on the side. The Alienware P4s will be luckily to get an hour just doing windows stuff (not browsing with wireless!), and a Rockdirect gets about 45 mins. Nice. And if you for a P4 then if it's a performance laptop then invest in extra fans coming out of your ears plus some weights lifting equipment to enable you to pump yourself up to be able to carry it around. If you like Alienware laptops then chuck them in the bin, and get a Rockdirect instead (or an AGP). Voodoo or PC Torque are pretty good too (there are more, but I dropped out of the scene after getting my laptop, and have a bad memory). Alienware laptops are basically too slow and too pricey. The Area 51, for example was always a *little* slower than the Rockdirect version, and was normally one to hundred quid more. Does have nice BIOS controlled eyes on the front though
Alienware desktops are a different story.
When it comes to power, then it depends what you want with Centrinos. When I bought mine, I liked that it was smaller than a small house, didn't get too hot, pretty much kept up with game benchmarks compared with the equivelent P4 (times the Mhz by 1.5 apparently - although think the Dothans slightly changed things - but my 2Ghz Dothan should be approx the same as a P4 3Ghz), and tend to look better. Some things are better than others. Just google it. But basically when the compared my 2Ghz Centrino with a few 3Ghz P4s with the same graphics card (ATI 9600 pro turbo 128mb) mine was in the middle somewhere with games benchmarking (including 3DMark200x), was slightly better at some things (office type stuff was better), and slightly worse at others. For example on the laptop forums someone posted SuperPI test results for 1 million decimal places. Nothing was as fast as my laptop (40 secs), even 3.4Ghz P4s (between 45-55 normally), apart from *one* AMD64 that did it in 39 seconds. Overall a Centrino should be fine power wise, and be a lot better size wise. Main downside is that since I got mine the graphics have come on a bit, to the point where they really only go inside P4s. The mobile X800 for example will get you, apparently, slightly better results than a 9800Pro (not the same as a desktop X800 though, think it's a cutdown version if I remember rightly). Pretty bloody good for a laptop basically. But you won't be getting it on a Centrino for a while (mainly heat problems).
AMD64 laptops are sort of inbetween. I almost went for one of these, as you can't deny the speed for the price, plus the laptops tend to be leaner than P4s (although not Centrinos in general). You also get inbetween battery life. Sort of 2-3 hours for a performance AMD64 compared to about 0.75-1.5 for a P4, and about 3-5 for a Centrino.
Look at
http://www.whatlaptop.co.uk/Forums/Default.aspx or
http://notebookforums.com/ And ignore the Alienware fanboys (Alienware is best. Not listening! Hands on ears! Alienware is best!) on the 2nd forum and the Anti-Dell (So you got £900 off a brand new PC, nothings gone wrong, and it has better benchmarks than all the PC's in the world put together? Sounds great! Dell? Argle, sounds rubbish!!!!!! NOOOO!!! (Even though I've never ever bought anything from them)) fanatics on the 1st forum. Hot air basically.
Quote: "These processors not only run fanless."
Mine has a fan. Just doesn't use it *all* the time. Start Doom 3 and you will hear it. Even my friends non-performance 1.4 Centrino has a fan. Now you hardly ever hear it, and it runs really cool, but it comes on now and again.
Cheers
I am 99% probably lying in bed right now... so don't blame me for crappy typing