What makes registers and L1 cache so much more expensive than L2/L3/RAM?

1 points by gtirloni ↗ HN

3 comments

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SRAM?

What do you mean by expensive?

Size vs speed?

L1 cache is optimized for speed. You can't make a large L1 cache... the access is too frequent meaning more bandwidth is needed. L1 has many parallel pipelines vs L2 or 3 which are larger caches, respectively, with less pipelining, respectively.
Bigger size means more latency. L1 needs to be fast due to frequent access. Is that what you mean by expensive?