If you've installed the game on a mechanical hd and not an ssd, download Contig at Technet, and power defragmenter front-end for it. Then do a folder defrag on the game folder, this will hopefully make those large data files in one continious file and not spread out all over the hd in 300+ fragments.
Another suggestion is try the game without the overclocking apps like FireStorm, MSI Afterburner, EVGA Precision etc. that you get with your graphics card, I noticed I got a lot more stuttering by simply having FireStorm running even without using any of the options.
I use an old version of EVGA Precision X 4.2.1xxx to control the fan, I tried the Precision X 5.2 something but it glitches in Diablo 3 which causes the mouse cursor dissapear, so I went back to the old version, which seems to work best for me. I didn't notice any noticeable detrimental effects in DA:I except from not being able to view the OSD statistics which I assume is due to Direct x 11 or DA:I being a x64 app.
Also see this thread It could only be a 970 issue though or general issue I don't know.
https://forums.geforce.com/default/topic/791910/geforce-900-series/dualmonitor-problem-main-monitor-turns-into-60hz-whenever-flash-is-on-secondary-monitor-970-sli/
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Whenever I run a game such as World of Warcraft (or any game) and I have a flash video present (or html5) on secondary monitor. The main monitor runs at 60hz and I get a frameloss of up to 50fps!
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