We use Visualcron to schedule hundreds of import/export jobs per hour. This, and the fact that there are multiple users managing jobs, makes the :00 time for example very busy.
From time to time, we go in and manually move things around to even out the load.

My suggestion for an elegant solution: Hourly timeslots.
* Divide the hour by a number of slots, 60 slots will enable you to schedule every minute. Or something like 30 slots, every 2 minutes. This (and maybe enabling timeslots altogether) should be configurable.
* In the job trigger settings there are already "interval" and "custom", add "hourly timeslot". Make a job be able to run in multiple timeslots, if it needs to run for example 4 times per hour.
* Create a "timeslot monitor/manager"-thingy where we can see how many jobs run in each time slot, so it is easy to distribute these jobs evenly over the hour to prevent high load on the server. It would also be nice to know the last and/or average runtime of those jobs. 9 jobs can run in 10 seconds and 1 job can take 5 min..

If the above could be implemented, I would be so happy. And so would my servers. ;)

/Andreas