NCQ enabled, 32 disks, 32 threads

heavy# zpool iostat 1
               capacity     operations    bandwidth
pool         used  avail   read  write   read  write
----------  -----  -----  -----  -----  -----  -----
...
test        40.0G  14.5T     14      0  1.30M      0
test        40.0G  14.5T     16      0  1.92M      0
test        40.0G  14.5T     36      0  3.77M      0
test        40.0G  14.5T  2.41K      0   308M      0
test        40.0G  14.5T  2.38K      0   304M      0
test        40.0G  14.5T  2.36K      0   303M      0
test        40.0G  14.5T  2.40K      0   307M      0
test        40.0G  14.5T  2.38K      0   304M      0
test        40.0G  14.5T  2.33K      0   299M      0
test        40.0G  14.5T  2.39K      0   306M      0
test        40.0G  14.5T  2.42K      0   310M      0
test        40.0G  14.5T  2.48K      0   318M      0
test        40.0G  14.5T  2.45K      0   314M      0
test        40.0G  14.5T  2.45K      0   314M      0
test        40.0G  14.5T  2.36K      0   303M      0
test        40.0G  14.5T  2.31K      0   296M      0
test        40.0G  14.5T  2.39K      0   306M      0
test        40.0G  14.5T  2.34K      0   299M      0
test        40.0G  14.5T  2.35K      0   300M      0
test        40.0G  14.5T  2.41K      0   309M      0
test        40.0G  14.5T  2.41K      0   308M      0
test        40.0G  14.5T  2.38K      0   305M      0
test        40.0G  14.5T  2.38K      0   305M      0
test        40.0G  14.5T  2.40K      0   307M      0
test        40.0G  14.5T  2.42K      0   309M      0
test        40.0G  14.5T  2.35K      0   301M      0
test        40.0G  14.5T  2.33K      0   298M      0
test        40.0G  14.5T  2.39K      0   306M      0
test        40.0G  14.5T  2.35K      0   301M      0
test        40.0G  14.5T  2.31K      0   296M      0
test        40.0G  14.5T  2.35K      0   301M      0
test        40.0G  14.5T  2.40K      0   307M      0
test        40.0G  14.5T  2.35K      0   301M      0
test        40.0G  14.5T  2.37K      0   304M      0
test        40.0G  14.5T  2.36K      0   303M      0
test        40.0G  14.5T  2.31K      0   296M      0
test        40.0G  14.5T  2.38K      0   304M      0
test        40.0G  14.5T  2.36K      0   302M      0
test        40.0G  14.5T  2.40K      0   307M      0
test        40.0G  14.5T  2.36K      0   302M      0
test        40.0G  14.5T  2.42K      0   309M      0
test        40.0G  14.5T  2.40K      0   308M      0
test        40.0G  14.5T  2.33K      0   299M      0
test        40.0G  14.5T  2.38K      0   304M      0
test        40.0G  14.5T  2.38K      0   304M      0
test        40.0G  14.5T  2.35K      0   301M      0
test        40.0G  14.5T  2.39K      0   306M      0
test        40.0G  14.5T  2.40K      0   308M      0
test        40.0G  14.5T  2.36K      0   302M      0
test        40.0G  14.5T  2.39K      0   306M      0
test        40.0G  14.5T  2.36K      0   302M      0
test        40.0G  14.5T  2.40K      0   307M      0
test        40.0G  14.5T  2.35K      0   301M      0
test        40.0G  14.5T  2.37K      0   304M      0
test        40.0G  14.5T  2.33K      0   298M      0
test        40.0G  14.5T  2.39K      0   305M      0
test        40.0G  14.5T  2.38K      0   305M      0
test        40.0G  14.5T  2.33K      0   298M      0
test        40.0G  14.5T  2.37K      0   304M      0
test        40.0G  14.5T  2.38K      0   305M      0
test        40.0G  14.5T  2.33K      0   298M      0
test        40.0G  14.5T  2.38K      0   305M      0
test        40.0G  14.5T  2.38K      0   305M      0
test        40.0G  14.5T  2.32K      0   297M      0
test        40.0G  14.5T  2.33K      0   299M      0
test        40.0G  14.5T  2.41K      0   309M      0
test        40.0G  14.5T  2.31K      0   295M      0
test        40.0G  14.5T  2.36K      0   302M      0
test        40.0G  14.5T  2.36K      0   302M      0
test        40.0G  14.5T  2.39K      0   306M      0
test        40.0G  14.5T  2.35K      0   301M      0
test        40.0G  14.5T  2.34K      0   300M      0
test        40.0G  14.5T  2.32K      0   298M      0
test        40.0G  14.5T  2.32K      0   297M      0
test        40.0G  14.5T  2.32K      0   298M      0
test        40.0G  14.5T  2.34K      0   299M      0
test        40.0G  14.5T  2.39K      0   306M      0
test        40.0G  14.5T  2.37K      0   303M      0
test        40.0G  14.5T  2.32K      0   298M      0
test        40.0G  14.5T  2.38K      0   304M      0
test        40.0G  14.5T  2.34K      0   299M      0
test        40.0G  14.5T  2.32K      0   297M      0
test        40.0G  14.5T  2.33K      0   298M      0
test        40.0G  14.5T  2.35K      0   301M      0
test        40.0G  14.5T  2.38K      0   305M      0
test        40.0G  14.5T  2.35K      0   300M      0
test        40.0G  14.5T  2.31K      0   295M      0
test        40.0G  14.5T  2.33K      0   298M      0
test        40.0G  14.5T  2.29K      0   293M      0
test        40.0G  14.5T  2.34K      0   299M      0
test        40.0G  14.5T  2.33K      0   298M      0
test        40.0G  14.5T  2.31K      0   296M      0
test        40.0G  14.5T  2.34K      0   300M      0
test        40.0G  14.5T  2.34K      0   300M      0
test        40.0G  14.5T  2.34K      0   300M      0
test        40.0G  14.5T  2.35K      0   301M      0
test        40.0G  14.5T  2.34K      0   299M      0
test        40.0G  14.5T  2.38K      0   305M      0
test        40.0G  14.5T  2.30K      0   294M      0
test        40.0G  14.5T  2.42K      0   310M      0
test        40.0G  14.5T  2.30K      0   295M      0
test        40.0G  14.5T  2.37K      0   303M      0
test        40.0G  14.5T  2.37K      0   304M      0
test        40.0G  14.5T  2.29K      0   293M      0
test        40.0G  14.5T  2.33K      0   298M      0
test        40.0G  14.5T  2.33K      0   299M      0
test        40.0G  14.5T  2.30K      0   294M      0
test        40.0G  14.5T  2.32K      0   297M      0
test        40.0G  14.5T  2.39K      0   305M      0
test        40.0G  14.5T  2.37K      0   303M      0
test        40.0G  14.5T  2.35K      0   301M      0
test        40.0G  14.5T  2.29K      0   294M      0
test        40.0G  14.5T  2.32K      0   297M      0
test        40.0G  14.5T  2.40K      0   307M      0
test        40.0G  14.5T  2.34K      0   299M      0
test        40.0G  14.5T  2.32K      0   298M      0
test        40.0G  14.5T  2.39K      0   306M      0
test        40.0G  14.5T  2.31K      0   295M      0
test        40.0G  14.5T  2.33K      0   298M      0
test        40.0G  14.5T  2.35K      0   301M      0
test        40.0G  14.5T  2.28K      0   292M      0
test        40.0G  14.5T  2.39K      0   306M      0
test        40.0G  14.5T  1.36K      0   175M      0