  We provide high-speed implementations for simulating reservoirs described by
$N$-coupled spin-torque oscillators. Here $N$ also corresponds to the number of
reservoir nodes. We benchmark a variety of implementations based on CPU and
GPU. Our new methods are at least 2.6 times quicker than the baseline for $N$
in range $1$ to $10^4$. More specifically, over all implementations the best
factor is 78.9 for $N=1$ which decreases to 2.6 for $N=10^3$ and finally
increases to 23.8 for $N=10^4$. GPU outperforms CPU significantly at $N=2500$.
Our results show that GPU implementations should be tested for reservoir
simulations. The implementations considered here can be used for any reservoir
with evolution that can be approximated using an explicit method.
