[MHo] 2017-07-31 There's something that I don't understand: Why ist the runtime of ====== set pool1 [tpool::create -minworkers 10 -maxworkers 20 -idletime 10] for {set i 1} {$i <= 20} {incr i} { lappend jobs [tpool::post $pool1 {after 10000} } ====== double the time of ====== set pool1 [tpool::create -minworkers 20 -maxworkers 20 -idletime 10] for {set i 1} {$i <= 20} {incr i} { lappend jobs [tpool::post $pool1 {after 10000} } ====== The first call runs ~20,xs, the second one, as expected, ~10,xs. The documentation states, the only difference is the time at which the workers are created - beforehand, or "on demand" when a post is done. As there are enough -maxworkers defined, what is limiting the operation then...?