Laptop - i7 or i5?

[Daz]

Does anyone have any experience with the i5 and i7 mobile chip(and sets)s? I'm looking to get a new laptop this year, and while I originally started looking at 13" models (portability is important, I'm off to a few geeky conferences this year and will hopefully do that sort of thing regularly), I'm finding it difficult to justify the inflated price for older generation tech and a screen resolution (9 times out of 10 1280x800, the other time it's 1366x768) that doesnt float my boat. The current crop of ~15"ers should be lighter than my current D820 so that'll have to do :p

Dell have some good offers on the studio 15 at the moment, along with double quicdo (6%) and a 5% voucher I can use, plus interest free credit, which is a bonus. I cant decide if I should cough up the extra for an i7 though - 8 threads is tempting, but I obviously wont be maxing that too often. I wonder if there's a noticeable affect on the battery life. It seems clever enough (http://www.pcpro.co.uk/blogs/2009/09/18/intel-core-i7-for-laptops-first-review/) with it's power management (as core usage count goes up, clock rate comes down), but I'd be interested in the opinions of anyone who's lived with one, ow who knows about such things :)

So, should I discount the i7 given that I need this thing to stay awake more than I need it to crunch the **** out of some numbers, or would the difference be negligible?

[Mark]

Don't make the mistake I made and get the highest spec you can. My D830 overheats if I 'crunch the **** out of some numbers' (I may give Dell warranty a ring when I get back from holiday).

Having said that, I know the differences between the i5 and i7 desktop chips but can't say the same for mobile. You're right about the power management though (even with mine if I'm just doing web/email it's absolutely fine).

[Davey_Pitch]

The only concern I would have with the i7 is the reports I've heard of it running very hit, much hotter than the i5. If you're not worried about this at all then I don't see much reason not to get the i7 if it's within your budget.

[Daz]

Trouble is, you'd think hot == power drinker, and that's what I'm trying to avoid :S

[LeperousDust]

Yeah it will be, heat is just wasted energy after all... I'm interested in this too, i can't afford anything yet, but i need to be looking at buying a laptop in the future before my netbook drives me over the edge, something portable yet "decent" is what I desire...