Well, how old is the install? You might want to try a fresh one (though I'm assuming you did this with the 120GB Intel SSD).
What I'd do is download ThrottleStop and see what's happening- if the machine is throttling back or not (and if so you can stop it- case in point is the Alienware M11x which has similar problems but I don't know if the same thing happens with the X301).
To download it and to see the guide, click here.
You might also want to take a look inside at the heatsink/fan assembly- you might be clogged with dust and that may make the machine throttle back.
Other than that, I can't really suggest anything else- other than to upgrade to a T420s or similar with a standard-voltage processor.
If they're in good condition, selling the two machines can net you enough for a T420s.
It might take a while to sell them, though, but if your price undercuts or breaks even with a lesser-spec'd machine you'll get rid of them faster (on fleabay it looks like you can net, oh, I don't know, 600 bucks apiece if not more).