Re: Cpu voltages. (intel)
You need to stress test it; simply running a game is not a sufficient test at all, IMO. Make sure it's stable and bump up the voltage little by little until it's stable on max load.
1.3v is pretty harmless, IMO, but I have little experience with Intel CPUs and have never had the i7, so I would make sure that other people (reviews, benchmarks, etc) echo my thoughts, just in-case Intels are weird and a wimpy volt kills them. xD
I've overclocked my AMD CPU from 3.6GHz to 4.5GHz and it's at 1.4v; this doesn't remotely bother me, and my motherboard (and likely the CPU) are capable of going over 1.5v so I'm really not worried. Unless electricity is uber expensive or money is uber tight, then I wouldn't worry too much, THAT SAID, it's always worth finding out from the horse's mouth (manufacturers or those that have extensively tested them, such as professional benchmarkers and testers, or a well experienced geek) what their gear should be at by max. Don't get me wrong, it's good to be careful when it comes to bumping up a voltage.