As said several times, you'll need an entirely new computer if you need better performance, an i5-3570k is recommended, with a dedicated GPU (check the 'minimum specs graphics card thread for more info, partially outdated).
If you absolutely need a laptop, an ivybridge @ 2.5-3.5 is a decent choice between price and performance, again, make sure it has a dedicated GPU (Nvidia/AMD), any laptop that comes with an ivybridge should have one of their better GPU so you may not need worry about the exact model number.
If you absolutely need a laptop, an ivybridge @ 2.5-3.5 is a decent choice between price and performance, again, make sure it has a dedicated GPU (Nvidia/AMD), any laptop that comes with an ivybridge should have one of their better GPU so you may not need worry about the exact model number.
......?????