What is the best processor i can install in a toshiba satellite l775 - S7111

[HB35G]

My core i3 is dying and slowing down and im in the process of installing 12gb ram in it and i want to install either a core i5 or i7
whats the best one i can upgrade to

 

[Ecky]

Your laptop has a BGA CPU, which means it's soldered to the motherboard. It cannot be replaced, but how do you know your i3 is dying? CPUs almost never die.

 

[DonkeyOatie]

You laptop uses a PGA socket, I think, so you are lucky. It can be upgraded. If it uses a BGA socket, no dice.

My top choices are i5 2430M and i7 2640M. All have same TDP and support the chipset and socket mentioned and were offered with versions of that laptop. Anything else would be a gamble. You could search the Internet as see what, if any, successful upgrades have been done.

How much will the new CPU cost? Is this a cost-effective solution? A modern $400 laptop may have superior performance.