OCing Help/Advice

So I recently pulled the trigger on a EVGA 980Ti Hybrid and I have to say that I am loving it. Seeing as it is water cooled I thought to myself "Gee, it sure would be a shame to have this thing sitting here running at default clock speeds." and with that I started my journey to overclock my graphic card. Using several programs (EVGA Precision, 3DMark Advance Edition, GPU-z and Heaven Benchmark and a spreadsheet for tracking the loads of numbers) I started overclocking it took me a while but I finally discovered that my card does not like any additional power whatsoever (is that unusual?). After I realized that I was able to get my card to what I thought was a stable overclock of +115mhz on the GPU and 150mhz on the MEM. But as soon as I tried to run with those settings in Heaven I was getting artificing (<--spelling correct?) quite frequently. I attempted to tone my settings down a bit but it didn't seem to help. Thoughts, comments, advice?

You need to do this

Step 1: Don't overclock

Step 2: Run the most difficult and hungry benchmark you can for 24 hours with the card.

Step 3: Overclock slowly till you find your wanted voltage and clock, GPU's in this case are much easier to OC

Step 4: Test this overclock with the same chugging benchmark for 1hour, if it artifacts restart from stock, if it doesnt and you like the temps and speed keep going.

Step 5: 24 hour final benchmark to make sure it is 100% stable. If it fails restart, if it doesnt you are golden. Make sure to monitor everything.