How many nodes can I run on Dual Core CPU?

Ant-Node (was Safe-node)
,
21

I managed to run four 8TB HDDs (228 nodes each) total of 912 nodes on i5 6600K 4 cores-4 threads (4.5GHz overclocked).
CPU average is at 50-55% but the load average is 3 times of CPU, average 12-12-12. Is this bad for nodes?