Prior to Maple 18, polynomial computations over ℤp called interpreted Maple library routines. This incurred significant overhead for small operations. For this release, we implemented Eval, Expand, and Divide in the kernel in C for the non-algebraic number case. Their performance is comparable to eval, expand, and divide, except that numbers are reduced to modulo p to prevent expression swell. The benchmark below times these operations for small polynomials on an Intel Core i5 4670 3.4 GHz with 16 GB RAM running 64-bit Linux.
The bar chart below shows the overall times for each n, with the times for Eval on top of the times for Divide and the times for Expand on the bottom.