
Solarflare
Server
Adapter
User
Guide
Solarflare
Adapters
on
FreeBSD
Issue
20
©
Solarflare
Communications
2017
314
Recommended
Forwarding
Tuning
shows
recommended
tuning
settings
for
forwarding:
TCP
Large
Receive
Offload
Disable
with:
ifconfig
sfxge<n>
‐
lro
TCP
Protocol
Tuning
Leave
at
default,
but
changing
does
not
impact
latency
Receive
Side
Scaling
Application
dependent
Buffer
Allocation
Method
Leave
at
default.
Some
applications
may
benefit
from
specific
setting.
PCI
Express
Lane
Configuration
Ensure
the
adapter
is
in
an
x8
slot
(2.0
or
later),
and
that
current
speed
(not
the
supported
speed)
reads
back
as
“x8
and
5GT/s”,
or
“x8
and
8GT/s”,
or
“x8
and
Unknown”.
CPU
Power
Management
Disable
with:
/etc/rc.d/powerd
stop
Memory
bandwidth
Ensure
memory
utilizes
all
memory
channels
on
system
motherboard
Table
76:
Forwarding
Tuning
Settings
Tuning
Parameter
How?
MTU
Size
Configure
to
maximum
supported
by
network:
ifconfig
sfxge<n>
mtu
<size>
Interrupt
moderation
Configure
an
explicit
interrupt
moderation
interval
with:
sysctl
dev.sfxge.<n>.int_mod=150
TCP/IP
Checksum
Offload
Leave
at
default
(Enabled).
TCP
Segmentation
Offload
Leave
at
default
(Enabled).
TCP
Large
Receive
Offload
Disable
with:
ifconfig
sfxge<n>
‐
lro
TCP
Protocol
Tuning
Leave
at
default
Receive
Side
Scaling
(RSS)
Leave
at
default
Table
75:
Latency
Tuning
Settings
Tuning
Parameter
How?