Ethernet Performance

Table of Contents

• Introduction
• Setup Details
• Layer 2 Performance
  • Configuration Details
  • Layer 2 Latency
• TCP/IP Performance
  • Configuration Details
    • TCP Throughput
    • UDP Throughput
• IEEE 802.1AS (gPTP) Performance Numbers
  • Configuration Details
  • Performance
• See Also

Introduction

This section provides the performance numbers of Ethernet drivers using CPSW peripheral in MCU+ SDK

Setup Details

SOC Details	Values
Core	R5F0 Core 0
Core Operating Speed	800 MHz
Memory Type	MSRAM
Cache status	Enabled
EVM Type	AM275-EVM
PHY Card used	DP83867 Add-on Card

Layer 2 Performance

Latency defination

Configuration Details

Configuration	Value
Processing Core	R5F0 Core 0
Core Frequency	800 MHz
Ethernet Interface Type	RGMII at 1 Gbps
Packet buffer memory	MSRAM (uncached)
Scatter-gather TX	Yes
Scatter-gather RX	Yes
UDMA interrupt pacing	NO
RTOS	FreeRTOS
RTOS application	Modified Enet CPSW Loopback Example example
Host PC tool version	nload
Rx packet length	200 B
Tx packet length	200 B

Layer 2 Latency

Parameter	CPU<->CPSW Latency Value (ns)	PHY (DP83867IR) Latency (from datasheet) in ns	Total Latency (ns)
RX Latency	12100	288	12388
TX Latency	6700	384	7084

TCP/IP Performance

Configuration Details

Configuration	Value
Processing Core	R5F0 Core 0
Core Frequency	800 MHz
Ethernet Interface Type	RGMII at 1 Gbps
Packet buffer memory	MSRAM (cached)
Hardware checksum offload	Enabled on both Tx and Rx Side
Scatter-gather TX	Yes
Scatter-gather RX	Yes
UDMA interrupt pacing	Yes (realized with timer based polling at 1ms interval)
RTOS	FreeRTOS
RTOS application	Enet Lwip CPSW Example in examples
TCP/IP stack	LwIP version STABLE-2_2_0_RELEASE
Host PC tool version	iperf v2.0.5
Number of Rx packet buffers	32
Number of Tx packet buffers	16

TCP Throughput

Test	Bandwidth (Mbps)	CPU Load (%)
TCP RX	93.1	28.5
TCP TX	92.8	28.5
TCP Bidirectional	RX=49.7 TX=51.2	29.75

Host PC commands:

• TCP Rx and Tx (Sequential):
  $iperf -c <evm_ip> -r
  
• TCP Rx and Tx (Bidirectional):
  $iperf -c <evm_ip> -d
  

UDP Throughput

Test	Datagram Length = 64B			Datagram Length = 256B			Datagram Length = 512B			Datagram Length = 1470B
	Bandwidth (Mbps)	CPU Load (%)	Packet Loss (%)	Bandwidth (Mbps)	CPU Load (%)	Packet Loss (%)	Bandwidth (Mbps)	CPU Load (%)	Packet Loss (%)	Bandwidth (Mbps)	CPU Load (%)	Packet Loss (%)
UDP RX	5	31	0.31	5	10	0.0	25	22	0.0	50	19	0.0
	10	48	19.0	15	24	0.0	50	42	0.39	60	26	0.0
	15	48	46	25	39	0.39	55	45	0.32	95	34	0.12
UDP RX (Max)	7	42	0.34	28	43	0.34	60	53	0.38	150	52	0.31
UDP TX (Max)	24.4	100	0	76.1	100	0.024	152	100	0.012	375	100	14

Host PC commands:

• Test with datagram length of 64B:
  $iperf -c <evm_ip> -u -l64 -b <bw> -r
  where <bw> is 5M, 10M, 15M, etc
  
• Test with datagram length of 256B:
  $iperf -c <evm_ip> -u -l 256 -b <bw> -r
  where <bw> is 25M, 50M, 100M, etc
  
• Test with datagram length of 512B:
  $iperf -c <evm_ip> -u -l 512 -b <bw> -r
  where <bw> is 25M, 50M, 100M, etc
  
• Test with datagram length of 1470B (max):
  $iperf -c <evm_ip> -u -b <bw> -r
  where <bw> is 25M, 50M, 100M, etc
  

IEEE 802.1AS (gPTP) Performance Numbers

Configuration Details

Configuration	Value
Processing Core	Main R5F0 Core 0
Core Frequency	800 MHz
Ethernet Interface Type	RGMII at 1 Gbps
Packet buffer memory	MSRAM (cached)
UDMA interrupt pacing	No (Disabled for gptp flow)
RTOS	FreeRTOS
gptp Configuration	Refer to Ethernet TSN gPTP Examples on quick sync configuration

Performance

Test	Measured value	802.1AS Parameters
802.1AS Time to Initial Sync	700ms	- sync interval = 15.625ms - pdelay req = 15.625ms - BMCA fixed configuration
802.1AS Sync Accuracy	70ns	- sync interval = 125ms - pdelay req = 1s

See Also

Ethernet And Networking Enet Lwip CPSW Example