Concurrency vs Parallelism

I am somewhat confused about the pricing model.

First of all, I assume the slider is broken. I choose 1x parallelism and 4 concurrency and the listing on the right displays 4 for both.

Second, once I make the choice to have 4 concurrent builds with 1 parallelism, can I also decide that one of my projects will use 2 parallelism?

Some of our projects are small and don’t need parallelism. Others are bigger and do use parallelism.

So my question is this: Do we get 4 containers and it is up to us to decide how to use them, concurrent or parallel? Or do we have to select a configuration and stick to it?


You choose a plan which then gives you ‘X’ amount of containers. Per project, you can choose how your builds use those containers. Setting parallelism to 1x (per project) means that that project’s builds will use 1 container. If your plan includes multiple containers, builds will run concurrently. This means two builds can run at once.

If you set parallelism to 2x or higher, then that project’s builds will require that amount of containers to run, splitting test between the containers.

You can set the parallelism amount per project, whenever you want. You decide when and how to use the containers you pay for.