Na página da carga da Wikipedia, você pode ver que eles estão relacionados, porque:
For single-CPU systems that are CPU bound, one can think of load
average as a percentage of system utilization during the respective
time period. For systems with multiple CPUs, one must divide the
number by the number of processors in order to get a comparable
percentage.
E a explicação mais longa sobre o carregamento informa que:
For example, one can interpret a load average of "1.73 0.60 7.98" on a
single-CPU system as:
during the last minute, the system was overloaded by 73% on average (1.73 runnable processes, so that 0.73 processes had to wait for a
turn for a single CPU system on average).
during the last 5 minutes, the CPU was idling 40% of the time on average.
during the last 15 minutes, the system was overloaded 698% on average (7.98 runnable processes, so that 6.98 processes had to wait
for a turn for a single CPU system on average).
Isto lhe dirá que a carga apontará o tempo do processador necessário para executar todos os processos em espera, assim, quanto maior a carga, menor o tempo ocioso que você terá até que a carga atinja 0 .