Solarflare
Server
Adapter
User
Guide
Solarflare
Adapters
on
FreeBSD
Issue
20
©
Solarflare
Communications
2017
312
CPU
Power
Management
The
powerd
service
controls
the
CPU
clock
speed
dynamically
according
to
current
processing
demand.
For
latency
sensitive
applications,
where
the
application
switches
between
having
packets
to
process
and
having
periods
of
idle
time
waiting
to
receive
a
packet,
dynamic
clock
speed
control
may
increase
packet
latency.
Solarflare
recommend
disabling
the
powerd
service
if
minimum
latency
is
the
main
consideration.
To
stop
powerd
,
type:
/etc/rc.d/powerd
stop
To
disable
powerd
across
reboots,
ensure
this
setting
is
present
in
/etc/rc.conf
:
powerd_enable="NO"
Memory
bandwidth
Many
chipsets
use
multiple
channels
to
access
main
system
memory.
Maximum
memory
performance
is
only
achieved
when
the
chipset
can
make
use
of
all
channels
simultaneously.
This
should
be
taken
into
account
when
selecting
the
number
of
memory
modules
(DIMMs)
to
populate
in
the
server.
For
optimal
memory
bandwidth
in
the
system,
it
is
likely
that:
•
all
DIMM
slots
should
be
populated
•
all
NUMA
nodes
should
have
memory
installed.
Please
consult
the
motherboard
documentation
for
details.
Server
Motherboard,
Server
BIOS,
Chipset
Drivers
Tuning
or
enabling
other
system
capabilities
may
further
enhance
adapter
performance.
Readers
should
consult
their
server
user
guide.
Possible
opportunities
include
tuning
PCIe
memory
controller
(PCIe
Latency
Timer
setting
available
in
some
BIOS
versions).
Tuning
Recommendations
The
following
tables
provide
recommendations
for
tuning
settings
for
different
applications.
Throughput
‐
Latency
Forwarding
‐