What is the Cost of an L1 Cache Miss?

Question

Edit: For reference purposes (if anyone stumbles across this question), Igor Ostrovsky wrote a great post about cache misses. It discusses several differen

Answer 1

3.2ns for an L1 cache miss is entirely plausible. For comparison, on one particular modern multicore PowerPC CPU, an L1 miss is about 40 cycles -- a little longer for some cores than others, depending on how far they are from the L2 cache (yes really). An L2 miss is at least 600 cycles.

Cache is everything in performance; CPUs are so much faster than memory now that you're really almost optimizing for the memory bus instead of the core.