Abstract

Dell commissioned Tolly to benchmark the performance, latency, and power consumption of the Dell PowerSwitch Z9864F-ON in AI fabric and high-density data center switching scenarios. The main focus of the project was to determine whether the switch could sustain full Layer 2 throughput across all 64 800GbE ports, while also characterizing latency behavior and energy efficiency under load.  

The PowerSwitch Z9864F-ON is positioned as a high-density open-networking aggregation switch for AI, machine learning, cloud, and large-scale compute and storage environments. In Tolly’s evaluation, the switch was tested using Keysight IxNetwork and an AresONE-S-800GE platform, with all 64 800GbE ports active in a snake topology for RFC2544 Layer 2 throughput testing. The switch delivered 100% line-rate aggregate throughput of 51.2Tbps at frame sizes of 512 bytes and above, including jumbo frames. At smaller frame sizes, throughput reached 46.54Tbps at 256 bytes, 24.93Tbps at 128 bytes, and 14.13Tbps at 64 bytes, all with zero frame loss at the reported rates.  

Latency testing was performed in a port-to-port topology using two 800GbE ports. Tolly measured both store-and-forward and cut-through forwarding modes. With store-and-forward enabled, latency ranged from 1,026ns to 1,068ns depending on frame size. In cut-through mode, latency ranged from 755ns to 922ns. For the larger frame sizes, tests ran at 100% line rate without packet loss, while smaller frames used slightly reduced offered load to preserve zero-loss conditions. These results position the switch as a low-latency option for high-speed Ethernet fabrics where forwarding delay matters in addition to raw throughput.  

Tolly also evaluated power consumption using the ATIS-0600015.03.2016 methodology for telecom and Ethernet switch products. The switch recorded 995.6W at idle with all ports up, 1057.5W at 30% traffic, and 1181.7W at 100% traffic. From these figures, Tolly calculated an ATIS weighted power value of 1063.73W and a telecommunication energy efficiency ratio of 48.1Gbps per watt. Overall, the report presents the Dell PowerSwitch Z9864F-ON as a very high-capacity 800GbE AI fabric switch that combines full line-rate performance at practical frame sizes, sub-microsecond cut-through latency, and strong power efficiency for dense next-generation Ethernet deployments.