$T=4  : 264 wallclock secs ( 3.80 usr + 2.09 sys =  5.89 CPU) -> 0.24 MByte/sec
$T=8  : 151 wallclock secs ( 5.31 usr + 1.89 sys =  7.20 CPU) -> 0.43 MByte/sec
$T=12 : 117 wallclock secs ( 6.55 usr + 2.41 sys =  8.95 CPU) -> 0.55 MByte/sec
$T=16 : 104 wallclock secs ( 7.73 usr + 2.83 sys = 10.56 CPU) -> 0.62 MByte/sec
$T=20 : 102 wallclock secs ( 8.36 usr + 2.80 sys = 11.16 CPU) -> 0.63 MByte/sec
$T=24 : 100 wallclock secs (10.11 usr + 3.00 sys = 13.11 CPU) -> 0.65 MByte/sec
$T=28 : 103 wallclock secs (11.89 usr + 3.02 sys = 14.91 CPU) -> 0.63 MByte/sec
$T=50 : 103 wallclock secs (18.89 usr + 4.30 sys = 23.19 CPU) -> 0.63 MByte/sec