Key ingredients to achieve effective 1/O asyne Copt stnct caching c/e Some mathematics Definitions efficiency= sending time (1) sending time+ping time data size sending time = speed (2) ping size speed ping time (3) Gives 1 efficiency (4) 1+ ping size data size efficiency data size= 1-efficiency ping size (5) latency ac mig 7/57 S.Ponce-CERNKey ingredients to achieve effective I/O 7 / 57 S. Ponce - CERN async IOopt struct caching c/c latency async msgQ Some mathematics Definitions efficiency = sending time sending time + ping time (1) sending time = data size speed (2) ping size = speed ∗ ping time (3) Gives efficiency = 1 1 + ping size data size (4) data size = efficiency 1 − efficiency ∗ ping size (5)