Is it worth the upgrade, I notice the difference between a 3rd gen. i5 and a 4th gen i7 can be hundreds of dollars. For the techies out there is the processing speed differential worth the price. thanks in advance...currently using an i5 equipped Toshiba laptop.
It depends on which what the computer is used for. If it's for web browsing/email/word processing/etc, then no, you won't really see a benefit. If you're playing high-end games, HD video encoding/decoding, CG graphics, or anything else computation-heavy, then yes, you will see an improvement. Also keep in mind, 4th gen Core CPUs require a different motherboard socket type than 3rd gen (LGA 1150 vs 1155 respectively). Meaning, if you want to upgrade from a 3rd gen i5 to a 4th gen i7, you will also need a new motherboard.
This may be too late to help you, but if it were my purchase, I wouldn't waste the extra money on an i5 in a notebook computer unless I were going to game on it, and I learned a long time ago that it is nothing but expensive, maddening frustration to try to game on a notebook. The most horsepower I'd need in a notebook would be an i3, or even a Pentium -- a dual core proc is what you want. BUT, I always avoid anything made by AMD because the procs run way too hot and that is going to cause you nothing but trouble in a notebook configuration no matter how good the heatsinks and fans are. I'm running an i7-2600k on my gaming rig and I don't even bother to OC at all. Dollar for dollar, the i5 proc is almost as good at about $100 less. Haswell? over Sandybridge or Ivybridge? Why? But if you really want to just hand money over to Intel, have a ball. Naturally they changed the board chipsets so that you can't use the older procs, thus, a Sandybridge proc can't be seated in a board designed for Haswell. BFD....
