This paper investigates the performance of two explicit, pseudo two-step Runge-Kutta methods of
order 5 and 8 for first-order nanstiff ODEs on a parallel shared memory computer. For expensive right-hand
sides the parallel implementation gives a speed-up of 3-4 with respect to the sequential one. Furthermore, we
compare the codes with the two efficient nonstiff codes DOPRI5 and DOP853. For problems where the
stepsize is determined by accuracy rather than by stability our codes are shown to be more efficient. ?? 1998
Elsevier Science Ltd. All rights reserved.
