Question: How to accelerate computation in Maple?

I solve system of ordinary differential equations numerically by method=rkf45 (Runge-Kutta Fehlberg method).

1. Maple 13 installed on the Linux x64. Processor – AMD Phenom (4 cores). When Maple computes it uses only one core but other three cores stand idle. How to impel to compute other cores?
2. When I solve system of ODE a calculation reaches closely 1 ns and stops. Maple writes that value of Maxfun exceeded. But I need solve system up to 10 μs. Correspondingly I increased Maxfun from 30,000 (default) up to 50,000,000. In this case computation reached 2 μs but computation time increased up to 7 hours. Then I increased Maxfun value up to 150,000,000 then computation exceeded 6 μs but it continues closely 20 hours. By the way one computation of this system is only one point of the plotting dependence. What can I do for accelerate computation?