I think it's perfectly on-topic, as evidenced by tags like computer-algebra-systems, sage, mathematica, and the number of well-received questions with said tags.
I do think it would be good to have some additional context. Perhaps
Broadly, how your code runs (i.e., the overall structure and the kind of function calls you make) and
What in particular seems to take a long time (are you making thousands of such computations, are the objects involved really complicated, is the problem just computationally demanding in general?).
Maybe whatever you're doing is very straightforward in theory and there's no need for any of that (I have no idea). Otherwise, I imagine such context will help people judge whether any software alternatives really could outperform Sage "out of the box".
Another possibility is that somebody intimately familiar with CAS will know some tricks that make these computations feasible, on whatever software you wind up using (e.g., perhaps somebody has ideas in the vein of Stein's Sage for Power Users, like using Cython or something).