Approximate cost to access various caches and main

Question

Can anyone give me the approximate time (in nanoseconds) to access L1, L2 and L3 caches, as well as main memory on Intel i7 processors?

While this isn't specifically a programming question, knowing these kinds of speed details is neccessary for some low-latency programming challenges.

Answer 1

Answer 2

+====================| |.pci............HOST|

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My apology for a "bigger-picture", but latency-demasking has also cardinal limits imposed from on-chip smREG/L1/L2-capacities and hit/miss-rates.

    |.pci............GPU.|
    |                    | FERMI [GPU-CLK] ~ 0.9 [ns] but THE I/O LATENCIES                                                                  PAR --                                                                     

                                                        
            

Answer 3

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Answer 6

|| ~masked