Also, in Equilab (for holdem at least), there are two ways to calculate: "Enumerate All" or "Monte Carlo".
When we perform an "Enumerate All" calculation for 2 players, it merely takes all possible combos and runs it against the other possible combos. If we select "Monte Carlo", then Equilab will select random cards and keep running these as simulations until we tell it to stop. The "Enumerate All" works great for simple scenarios, like 2 players, or river scenarios where there isn't a lot of mystery left.
Be aware of the calculation setting you are using. It may take Monte Carlo many millions of games before the results stabilize around the result you are looking for.