Ethernet Performance

Table of Contents

• Introduction
• Setup Details
• Layer 2 Performance
  • Configuration Details
    • For R5F
    • Layer 2 Latency
• Layer-2 Hardware Switching Latency for CPSW
  • Test Setup
  • CPSW Latency for RGMII
• TCP/IP Performance
  • Configuration Details
    • TCP Throughput
    • UDP Throughput
• See Also

Introduction

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

Setup Details

SOC Details	Values
Core	R5F
Core Operating Speed	800 MHz
Memory Type	MSRAM
Cache status	Enabled
EVM Type	AM243x-LP/AM243x-EVM

Layer 2 Performance

Latency defination

Configuration Details

For R5F

Configuration	Value
Processing Core	Main R5F0 Core 0
Core Frequency	800 MHz
Ethernet Interface Type	RGMII at 1 Gbps
Packet buffer memory	MSRAM
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 Latency (from datasheet) in ns	Total Latency (ns)
RX Latency	14000	193	14193
TX Latency	7000	384	7384

Layer-2 Hardware Switching Latency for CPSW

Configuration	Value
EVM Type	AM243x-LP E3
CPSW CPPI Frequency	320 MHz
Ethernet Interface Type	RGMII
PHY model number	DP83869
Ethernet Cable Spec	CAT-6
Sample size	10 Million Packets
RTOS application	Modified Enet Layer 2 CPSW SWITCH Example example

Test Setup

Connections for Latency Measurement

CPSW Latency for RGMII

Datagram Length	Latency @ 1Gbps link (in us)		Latency @ 100Mbps link (in us)		Latency @ 10Mbps link (in us)
	Without Cut-Through	With Cut-Through	Without Cut-Through	With Cut-Through	Without Cut-Through	With Cut-Through
64 Bytes	1.8	1.7	7.9	7.8	73.4	71.9
256 Bytes	3.1	2.0	23.0	13.8	227.3	135.6
512 Bytes	5.2	2.0	43.5	13.8	432.0	135.6
1518 Bytes	13.3	2.0	124.0	13.8	1237.0	135.6

TCP/IP Performance

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)
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 interrupt pacing)
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 v2.0.10
Number of Rx packet buffers	32
Number of Tx packet buffers	16

TCP Throughput

AM243-LP

Test	Bandwidth (Mbps)	CPU Load (%)
TCP RX	93	34
TCP TX	93	34
TCP Bidirectional	RX=93 TX=93	63

AM243-EVM

Test	Bandwidth (Mbps)	CPU Load (%)
TCP RX	93.3	43
TCP TX	93	72
TCP Bidirectional	RX=81.5 TX=81.5	99

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

AM243-LP

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	25	0.0	5	7	0.0	25	18	0.0	50	16	0.0
	10	36	22	15	19	0.0	50	34	0.1	65	21	0.0
	15	36	48	25	31	0	65	42	4.6	95	68	0.0
UDP RX (Max)	7	32	0.8	32	37	0.9	61	41	0.8	110	78	2.4
UDP TX (Max)	40	100	0.0	90	100	0.0	161	100	0.0	535	100	0.0

AM243-EVM

Test	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 (%)
UDP RX	5	14	0.0	25	27	0.011	50	25	0.051
	10	21	0.08	50	49	0.35	65	31	0.18
	25	46	0.22	65	59	6.5	95	43	0.28
UDP RX (Max)	28	50	0.29	59	57	0.6	155	68	0.26
UDP TX (Max)	68	100	0.0	136	100	0.0	389	100	0.0

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 -l256 -b <bw> -r
  where <bw> is 25M, 50M, 100M, etc
  
• Test with datagram length of 512B:
  $iperf -c <evm_ip> -u -l512 -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
  

See Also

Ethernet And Networking Enet Lwip CPSW Example