When using Network I/O Control, at high packet rates, Tx packets might drop and cause performance issues

Products

• VMware vSphere ESXi 8.0

Issue/Introduction

Due to limitations in the default configuration parameters,
when using Network I/O Control at high packet rates, Tx packets might drop and cause performance issues.

Environment

VMware ESXi 8.0

Resolution

This issue is resolved in the VMware ESXi 8.0 Update 3j (Build 25429389)

The fix changes the default value of Network I/O Control to allow for more Tx worlds to handle traffic with higher speed NICs.
The fix involves changes to the default config parameters:

    NetSchedInFlightQueueBytesScaler from 2 to 4
    NetSchedHClkLeafQueueDepthPktMAX from 5120 to 8192

For NICs with linkspeed < 100G, double the number of tx queues for hClock
    Link Speed # pNIC Tx queues hClock uses 10Gbps 2 25Gbps 4 50Gbps 8
    NetSchedHClkLeafQueueDepthPkt from 640 to 1024

Additional Information

VMware ESXi 8.0 Update 3j Release Notes
https://techdocs.broadcom.com/us/en/vmware-cis/vsphere/vsphere/8-0/release-notes/esxi-update-and-patch-release-notes/vsphere-esxi-80u3j-release-notes.html