I've done some more tests. Here they are all: io1, 100 GB SSD, 1000 IOPS effective_io_concurrency=0 Execution time: 40333.626 ms effective_io_concurrency=1 Execution time: 163840.500 ms effective_io_concurrency=2 Execution time: 162606.330 ms effective_io_concurrency=4 Execution time: 163670.405 ms effective_io_concurrency=8 Execution time: 161800.478 ms effective_io_concurrency=16 Execution time: 161962.319 ms effective_io_concurrency=32 Execution time: 160451.435 ms effective_io_concurrency=64 Execution time: 161763.632 ms effective_io_concurrency=128 Execution time: 161687.398 ms effective_io_concurrency=256 Execution time: 160945.066 ms effective_io_concurrency=256 Execution time: 161226.440 ms effective_io_concurrency=128 Execution time: 161977.954 ms effective_io_concurrency=64 Execution time: 159122.006 ms effective_io_concurrency=32 Execution time: 154923.569 ms effective_io_concurrency=16 Execution time: 160922.819 ms effective_io_concurrency=8 Execution time: 160577.122 ms effective_io_concurrency=4 Execution time: 157509.481 ms effective_io_concurrency=2 Execution time: 161806.713 ms effective_io_concurrency=1 Execution time: 164026.708 ms effective_io_concurrency=0 Execution time: 40196.182 ms gp2, 100 GB SSD effective_io_concurrency=0 Execution time: 40262.781 ms effective_io_concurrency=1 Execution time: 98125.987 ms effective_io_concurrency=2 Execution time: 55343.776 ms effective_io_concurrency=4 Execution time: 52505.638 ms effective_io_concurrency=8 Execution time: 54954.024 ms effective_io_concurrency=16 Execution time: 54346.455 ms effective_io_concurrency=32 Execution time: 55196.626 ms effective_io_concurrency=64 Execution time: 55057.956 ms effective_io_concurrency=128 Execution time: 54963.510 ms effective_io_concurrency=256 Execution time: 54339.258 ms io1, 1 TB SSD, 3000 IOPS effective_io_concurrency=0 Execution time: 40691.396 ms effective_io_concurrency=1 Execution time: 87524.939 ms effective_io_concurrency=2 Execution time: 54197.982 ms effective_io_concurrency=4 Execution time: 55082.740 ms effective_io_concurrency=8 Execution time: 54838.161 ms effective_io_concurrency=16 Execution time: 52561.553 ms effective_io_concurrency=32 Execution time: 54266.847 ms effective_io_concurrency=64 Execution time: 54683.102 ms effective_io_concurrency=128 Execution time: 54643.874 ms effective_io_concurrency=256 Execution time: 42944.938 ms gp2, 1 TB SSD effective_io_concurrency=0 Execution time: 40072.880 ms effective_io_concurrency=1 Execution time: 83528.679 ms effective_io_concurrency=2 Execution time: 55706.941 ms effective_io_concurrency=4 Execution time: 55664.646 ms effective_io_concurrency=8 Execution time: 54699.658 ms effective_io_concurrency=16 Execution time: 54632.291 ms effective_io_concurrency=32 Execution time: 54793.305 ms effective_io_concurrency=64 Execution time: 55227.875 ms effective_io_concurrency=128 Execution time: 54638.744 ms effective_io_concurrency=256 Execution time: 54869.761 ms st1, 500 GB HDD effective_io_concurrency=0 Execution time: 40542.583 ms effective_io_concurrency=1 Execution time: 119996.892 ms effective_io_concurrency=2 Execution time: 51137.998 ms effective_io_concurrency=4 Execution time: 42301.922 ms effective_io_concurrency=8 Execution time: 42081.877 ms effective_io_concurrency=16 Execution time: 42253.782 ms effective_io_concurrency=32 Execution time: 42087.216 ms effective_io_concurrency=64 Execution time: 42112.105 ms effective_io_concurrency=128 Execution time: 42271.850 ms effective_io_concurrency=256 Execution time: 42213.074 ms Regards, Vitaliy
