[Dylan16807]

Ideally you want L3 to be fast, but it's going to be somewhat slow just by the nature of being large. And talking to ram is going to be slow even if the intra-chip pathways are infinitely fast. An extra few percent off-core latency isn't the end of the world if it lets you fit ten times as much computation on the die. L2 and L1 won't be affected.

And encoding video is nearly the platonic ideal of not caring about memory latency. You could easily make memory requests ten thousand cycles before you need the results. You just need throughput.