
Issue 11
© Solarflare Communications 2014
97
Solarflare Server Adapter
User Guide
Recommended Latency Tuning
Memory bandwidth
Ensure Memory utilizes all memory channels on system
motherboard
Intel QuickData (Intel chipsets
only)
Enable in BIOS and install driver:
modprobe ioatdma
Table 23: Latency Tuning Settings
Tuning Parameter
How?
MTU Size to maximum
supported by network
Leave at default
Interrupt moderation
Disable with:
ethtool -C <ethX> rx-usecs-irq 0
TCP/IP Checksum Offload
Leave at default
TCP Segmentation Offload
Leave at default
TCP Large Receive Offload
Disable using sysfs:
echo 0 > /sys/class/net/ethX/device/lro
TCP Protocol Tuning
Leave at default, but changing does not impact latency.
Receive Side Scaling
Application dependent
Interrupt affinity & irqbalance
service
Stop irq balance service:
/sbin/service irqbalance stop
Interrupt affinity settings are application dependent
Buffer Allocation Method
The Solarflare driver now supports a single optimized buffer
allocation strategy and any value set by the rx_alloc_method
parameter is ignored.
PCI Express Lane
Configuration
Ensure current speed (not the supported speed) reads back
as “x8 and 5Gb/s” Or “x8 and Unknown”
CPU Speed Service (cpuspeed)
Disable with:
/sbin/service cpuspeed stop
Memory bandwidth
Ensure Memory utilizes all memory channels on system
motherboard
Table 22: Throughput Tuning Settings
Tuning Parameter
How?