Buying a U6v (T9400 2.53GHZ) any heat/battery issues?

I am going to buy an ASUS U6v.

The stock configuration offered by 90% of vendors includes a P8400 2.26GHZ 3MB.

However, a handful of vendors also offer it with a T9400 2.53GHZ 6MB.

Example: http://btotech.com/config.asp?config_id=u6v-a1-custom

I am willing to pay for the upgrade, as this laptop will be my main work computer, but I have a few questions:

1. Is the T9400 in a U6v allowed and suggested by ASUS? Also, will the stock ASUS warranty still apply?

2. Will using this faster processor severely increase heat output, or severely decrease battery life?

The U6v already sports the most powerful GPU in any 12" laptop that I know of. I do not wish to go crazy with the specs and end up burning a hole in my lap before my 30 minutes of battery life are used up.

 

1. If the reseller customizes the notebook, the ASUS warranty is void, and you are supported by the reseller only. That being said, BTOtech is a pretty well trusted reseller around here. In any case, consider whether you really need the upgrade before you decide to apply it.

2. That depends on the TDP of the CPU. Checking the Intel pages for the two CPUs should tell you the difference. Although, the TDP is the MAXIMUM heat output of the CPU, and doesn't give a good indication of the power consumed and heat outputted at idle -- but it gives you an idea, nevertheless.

 

The 8-cell is not an option in the US (here it ships with batteries x2, 3 & 6 cell). Battery estimates for the U6 with that are ~3 hours, maybe 3.5 with tweaking. You can get a U6 9-cell aftermarket for $149 at BTOTech.

Um, I'm not sure this is correct.

I'm reasonably sure, although I can't find anywhere in the linked review at TR that states this, that the near 6-hour battery time is using both the 3 and 8 cell batteries combined. My logic here is that the 6 cell confirmed runtime on the U6sg version is around 3 hours, so it defies probability that you would somehow gain 2.5-3 hours from only 2 additional battery cells, even with Montevina's chipset improvements - if you say that you're looking at 11 total cells, however, it works. And then there's Asus' inability to code a decent power management ACPI in current models....

Swapping out the cpu will probably not provide any appreciable performance difference in the vast majority of uses, with the exception of high cpu-intensive operations like encoding.