So I recently got a GTX 760 by msi, the OC version, and it runs all the games I play at high setting smoothly, but when I try to overclock it, it seems to almost shut down momentarily and then the performance drops incredibly. The only way i found to fix this is to only install the graphics driver and not allowing for GPU boost to overclock. I think this may be because I only have a 430 watt psu. Here are my specs.
Hey Yo Nick! I think your right about the PSU. If you still have the case to the GPU it should say on there what the power draw is. And when your overclocking its always good to have more then less; if you didn't know this goes for a lot things. So it's time to bro.
Very much doubt you psu is the issue unless it is faulty, those cx430 units punch well above their weight. You'd be lucky to be pulling 250-280w @ full load (cpu & gpu).
My rig pulls just on 500w from the wall @ full load and 250w in Grid 2. (2x oc'd 760's etc, see my profile). Just to give you an idea.
Your gpu is already overclocked out of the box so manually overclocking it further will most likely lead to instability as the card has reached its limits. Which would explain the card messing its pants when you oc manually.