I didn't say that it can't be upgraded. Your original question was:
YWZMatt :
Anyways, will I get a performance increase that's worth the money with the upgrade?
The answer is no.
The CPU isn't doing much of the heavy lifting in these games. It's mostly on the GPU. The i5 is not bottlenecking the graphics card that you have. You can upgrade the CPU and overclock and then SLI the GTX 770. That would yield a good performance boost. If Skyrim is using up all the VRAM, then SLI isn't going to help. You will want a card with more VRAM or don't use so many mods.
Watch Dogs is heavily unoptimized. A patch fix is supposed to be out in September. Even a GTX 780 Ti has issues running it on Ultra settings.