Should I spend an extra $100 for 4mb's of L2 rather than being happy with 2mb's of L2 on a laptop? This post IS NOT a duplicate posting, but specifically about L2 cache which was not able to be answered on the laptop forums.
Please read through that short thread above if you have any questions as they may have already been addressed.
Cache does not play a big role.
However, a very low FSB could play a big role.
If one laptop has a highe FSB it could be a big issue.
There were some tests comparing the E4300 vs the E6300.
The E4300 has a FSB of 800 vs 1066 for the E6300.
At Stock speeds, the E6300 was well ahead.
When both chips were OC'd to the same high speed and both had higher FSB speeds, they were about equal.
Once you get to 1066 FSB and beyond, FSB becomes less of an issue too.
Just something to watch for.
However, Most Laptops have a low FSB so there may not be much you can do.
A low FSB on a laptop is not necessarily a bad thing. The CPU idle speed is computed as 1.5x the FSB speed, so the lower the FSB speed, the lower the idle speed, and the longer and cooler it will run on battery. The newest 800 MHz FSB Core 2 Duos can drop their FSBs to 533 MHz from the full 800 during idle, so that will help you save some battery life as it drops the idle speed from 1200 MHz to 800 MHz.
But I'd not worry about a fast laptop CPU anyway. The HDD is by far and away the slowest thing in the machine unless you pay a grand for a 64 GB SSD. My laptop has a 1.067 GHz Core 2 Duo ULV U7500 with 2 MB L2 and a 533 MHz FSB and it is plenty fast for anything you'd want to use a portable notebook for. But even with a standard 2.5" SATA hard drive in it, the HDD is still the slowest thing in the machine.