Sorry new to the forum, I checked out the other categories, and didn't really know where to put this. HOWEVER, I still want to point this out to the devs because I love this freaking game and wish to see it become more successful.
It would seem that the further you go out from home base, the FPS progressively becomes worse. Usually it starts at 60FPS, sometimes dips. But I can expect that. The further you go out (even before the horse update) the FPS just dips down more and more. Now that horses are around, the FPS dips are more faster. I love the horses as they move fast as crap and you can really cover a large distance in a short amount of time. Which is useful for finding Savannah's, deserts, snow biomes, etc.
I put up a video on Youtube showcasing the FPS dip as I was testing the horses out.
My PC specs are above the minimum recommended for the game. EVGA Geforce GTX980 TI, 16GB Ram, i7 3770k. When I livestream it usually dips lower (as expected since OBS Studio is capturing footage). When I am playing without streaming its always a consistent 60FPS.
Thanks for allowing me to point this out. Love Rising World a lot. I look forward to more content!