Yeah, I forgot all about this thread.
Sometime after I started this thread i completely disassembled the laptop. The CPU is upgradeable, but can only be upgraded to a CPU with integrated graphics (the only ones with integrated graphics are dual cores). So that puts the highest cpu for this machine at an i7 640m.
I ended up just replacing the ram with an 8gb kit and putting in an ssd. Plenty fast for browsing the web and light photoshop usage.
And one other thing: tomshwmarcc, this thread is one and a half years old
Hey hambone, I'm looking to upgrade my CPU as well. I've already upgraded to 8GB too and I've put in a Hybrid harddrive. I have Lenovo Thinkpad Edge 14 with an i3 M350. Do you know if it would it work to upgrade to that i7 M640?