> network -> disk -> ram -> L2 cache -> L1 cache -> register It's more and more like network/disk -> L3 cache -> L2 cache. DRAM is pretty slow. Because PCIe c

> network -> disk -> ram -> L2 cache -> L1 cache -> register It's more and more like network/disk -> L3 cache -> L2 cache. DRAM is pretty slow. Because PCIe controller is anyways on the same chip as L3 cache, there's no reason to send the data on a long trip to DRAM and back. Until, of course, when the cache line gets evicted for reason or another.