Thank you so much!!!
Now I understand, I'm planning to build my own rig, but before that I want to get some expertise in GPU mining.
I thought that a nice experiment could be mounting an external GPU on another cheap Lenovo laptop I have, so if some issues comes up I can learn how to throubleshoot them before investing 1000£ in building my own RIG.
Do you guys consider a Radeon R9 270X a good one?
I'd like to go for the best Hashes/Cost ratio now before investing my whole budget.
Which one do you suggest?