User Manual

PerformanceRev 2.1-1.0.6
Mellanox Technologies
130
7.2 Performance Tuning for Linux
You can use the Linux sysctl command to modify default system network parameters that are set
by the operating system in order to improve IPv4 and IPv6 traffic performance. Note, however,
that changing the network parameters may yield different results on different systems. The
results are significantly dependent on the CPU and chipset efficiency.
7.2.1 Tuning the Network Adapter for Improved IPv4 Traffic Performance
The following changes are recommended for improving IPv4 traffic performance:
• Disable the TCP timestamps option for better CPU utilization:
• Enable the TCP selective acks option for better throughput:
• Increase the maximum length of processor input queues:
• Increase the TCP maximum and default buffer sizes using setsockopt():
• Increase memory thresholds to prevent packet dropping:
• "Enable low latency mode for TCP:
7.2.2 Tuning the Network Adapter for Improved IPv6 Traffic Performance
The following changes are recommended for improving IPv6 traffic performance:
• Disable the TCP timestamps option for better CPU utilization:
Memory Memory speed Max performance
Memory channel mode Independent
Node Interleaving Disabled / NUMA
Channel Interleaving Enabled
Thermal Mode Performance
sysctl -w net.ipv4.tcp_timestamps=0
sysctl -w net.ipv4.tcp_sack=1
sysctl -w net.core.netdev_max_backlog=250000
sysctl -w net.core.rmem_max=4194304
sysctl -w net.core.wmem_max=4194304
sysctl -w net.core.rmem_default=4194304
sysctl -w net.core.wmem_default=4194304
sysctl -w net.core.optmem_max=4194304
sysctl -w net.ipv4.tcp_rmem="4096 87380 4194304"
sysctl -w net.ipv4.tcp_wmem="4096 65536 4194304"
sysctl -w net.ipv4.tcp_low_latency=1
sysctl -w net.ipv4.tcp_timestamps=0
Table 19 - Recommended BIOS Settings for AMD Processors
BIOS Option Values