Dell Inspiron 6400 / E1505 CPU upgrade?

I DID search but found conflicting information.

I have a Dell here that I just picked up free due to having a busted screen and a bad battery. Luckily I have a HUGE pile of dead laptops and had these parts!

The laptop says Inspiron 6400 on it but the service tag shows up as a E1505 on Dell's site. The service tag is 4Q38YB1 if that helps.

I put two 1gb DDR2-800 sticks in (though it comes up as 533MHz) and a 120gb SATA drive in.

I loaded XP Home (as that's the license on the bottom) and I'm ready to start tinkering.

Now, this model has the T2250 Core Duo in it. Far as I can find, it has the i945 chipset.

What is the fastest Core2Duo I can slap in there? I've already put a fast drive in there with 16mb cache but looking for some more speed.

 

You can use any Socket M processor in the 6400/E1505. The fastest such processor is the T7600, though the T7400 and T7200 are not much slower and arguably a much better value.

 

Is the Socket M older than the Socket P? My other laptop is a Socket P and I have a T5850 in that... wondering if I can get this Dell to the same level or higher of it I'm better off with my other laptop.

 

Socket M is older than Socket P. Nonetheless, a T7200 or T7400 is probably just as fast if not faster than a T5850.