Its pretty hard to find people that go in-depth enough to mention the phenomenon. Wendel sorta covered it in this thread:
Basically you want the memory latency to remain low as more bandwidth is used up. In this example, the latency of the memory increased by ~20% as peak bandwidth is approached, which is pretty decent:
In this example the memory latency increased by ~280% as peak bandwidth is approached which is not good and will cause all kinds of slow downs that can be hard to diagnose:
