1) What test did you run to determine your performance?
Benchmarks aren't always completely comparable as some people have heavily overclocked components. Plus, if using something like "Firestrike" make sure you aren't comparing "Firestrike Ultra" results by accident.
2) Latest NVidia drivers?
3) Connected the monitor to the graphics card (not motherboard)?
4) How CLOSE is performance?
A stock GTX980 is about 15% difference to GTX970 but again they can be overclocked so it's hard to compare. Even at the EXACT same preset a cooler system can get slightly higher performance due to how dynamic GPU throttling works.
The CPU and GPU calculations in benchmarks are often added together. Your i7 has hyperthreading but the i7-4690K has...