I'm confused how/when Batch decides to spin up a new EC2 instance vs reusing the same one. In one of my steps I requested

cpu=64, memory=384_000, gpu=1

and it's correctly running that task on a

g3.16xlarge

instance (which has 64 vCPU, 488 GiB memory and 4 GPUs). I am expecting no other tasks to be scheduled on that instance since the core count is maxed out, but I see another 24 tasks (with

cpu=1, memory=4

) running on the same instance. What is going on?