The highest performance is with three clients. With more clients, the SoC struggles to keep up. The following screenshots show the hardware utilization during these intense multi-client tests.
With several clients connected and asking for high amounts of data at the same time, CPU utilization is very high. So if you believe you can replicate such a usage scenario often, this is not the ideal NAS for you. Lastly, RAM utilization is low in this scenario, with the SoC setting the limits in multi-client network transfers.
Despite the heavy load, the system temperature is kept low at 42 °C.