heterogeneous kubernetes cluster, container performance difference
Yes. If two Pods both specify e.g. 1000m CPU and they run on different nodes, they both get an equivalent of 1 CPU core on their node. If one node has a faster CPU than the other node, then the Pod on this node correspondingly runs faster.
The same applies for other hardware characteristics of the nodes, e.g. the availability of a GPU, the speed of the memory and cache, etc.
If you want a more deterministic behaviour, you can categorise your nodes with labels or assign taints to them. Then, on the Pod side, you can influence what node a Pod gets scheduled to with tolerations, node selectors, node affinities, or even a custom scheduler.