Key ingredients to achieve effective 1/O asyne Copt stnct caching c/e Some (bad)numbers Consequences for 10KB blocks Usage Speed Latency Ping Size Efficiency CC 1GBs-1 100μs 10kB 50% cc 10GBs-1 100μs 100kB 9% WAN 1GBs-1 10ms 1MB 1% WAN 10GBs-1 10ms 10MB 1%0 UK-JP 10GBs-1 250ms 250MB 0.04%0 latency ac mig 8/57 S.Ponce-CERNKey ingredients to achieve effective I/O 8 / 57 S. Ponce - CERN async IOopt struct caching c/c latency async msgQ Some (bad) numbers Consequences for 10KB blocks Usage Speed Latency Ping Size Efficiency CC 1 GB s−1 100 ➭s 10 kB 50% CC 10 GB s−1 100 ➭s 100 kB 9% WAN 1 GB s−1 10 ms 1 MB 1% WAN 10 GB s−1 10 ms 10 MB 1h UK-JP 10 GB s−1 250 ms 250 MB 0.04h