I'm assuming "i5-3700K" is supposed to be "i7-3770K," and at 4.5 GHz it is a faster CPU than your i7-4790K at 4.0 GHz - sorry, but one generation is not a large enough IPC increase to make up for a 12.5 % frequency difference.
For what it's worth, a first gen Core i3 with SATA300 ports and an SSD should load faster than an i7-6700K with a mechanical hard drive every single time.
It sounds more like the software was coded to be faster on AMD. Even when AMD was whipping the crap out of Intel at gaming (Athlon Classic, Athlon Thunderbird, Athlon XP and Athlon 64), Intel was always faster at media and scientific calculations/modelling. These days Intel is even further ahead. Look at boincstats to see several hundred thousand computers' results at scientific modelling and calculations - AMD doesn't feature in any top list unless you're talking a 48+ core quad socket setup.