Ima on an intel dual core laptop with 4 gigs and shared ram... and sins runs great... (and with windows 7... i got a bit more ram to play with as well) highest gets laggy... but its respectible enough to get awesome screen shots... expecially on smaller maps... but for normal sized battles... i can run it on high just fine. for... say... 5v5 pugs... i turn it down to medium so that it doesnt get too jerky... and besides... on multiplayer... your definatly not zoming in on a single fighter and watching your fleets battle it out... your way to busy with other things... like making sure your fleet doesnt die.
Now... if you like playing with some of the crazy mods... like say distant stars... highest gets almost unplayable... even in small battles... hehe... if 7 deadly sins ever gets updated... they TELL you that highest is a Guarenteed mini-dump... and should obviously not be done.
NOw... so while you will be fine... let me state the obvious that a better computer plays better. (like... if you got a actual graphics card instead of a ram leech... although honestly... if it can use 1750 for graphics... if you got 6 gigs of ram... holly shizznits... almost 2 gigs for graphics... almost 4 gigs for game... and the bit left over for windows... that would play guuud. *drools*)