Solarflare
Server
Adapter
User
Guide
Solarflare
Adapters
on
Windows
Issue
20
©
Solarflare
Communications
2017
234
Solarflare
network
adapters
optimize
RSS
settings
by
default
on
Windows
operating
systems
and
offer
a
number
of
RSS
interrupt
balancing
modes
via
the
network
adapter's
advanced
property
page
in
Device
Manager
and
Solarflare's
adapter
management
tools.
The
number
of
RSS
queues
can
be
adjusted
to
suit
the
workload:
•
The
number
of
RSS
CPUs
is
limited
by
the
number
of
RSS
queues.
The
driver
does
not
target
multiple
RSS
queues
to
the
same
CPU.
Therefore:
‐
It
is
best
to
set
the
maximum
number
of
RSS
queues
to
be
equal
to
the
maximum
number
of
RSS
CPUs
(or
the
next
higher
setting
if
the
equal
option
is
unavailable).
‐
The
number
of
queues
can
be
reduced
in
order
to
isolate
CPU
cores
for
application
processing.
‐
The
number
of
queues
can
be
increased
to
spread
the
load
over
more
cores.
This
will
also
increase
the
amount
of
receive
buffering
due
to
a
larger
number
of
RX
queues.
NOTE:
If
hyper
‐
threading
is
enabled,
RSS
will
only
select
one
thread
from
each
CPU
core.
•
The
current
number
of
queues
can
be
get
and
set
using
either
SAM,
or
the
Network
Adapter’s
Advanced
Properties
Page.
•
On
Windows
Server
2012
and
later,
the
current
number
of
RSS
queues
can
also
be
queried
and
set
from
the
PowerShell
with
the
Get
‐
NetAdapterRss
and
Set
‐
NetAdapterRss
cmdlets.
The
set
of
RSS
CPUs
can
also
be
adjusted:
•
For
low
latency
low
jitter
applications
select
the
NUMA
scaling
static
RSS
profile.
Set
both
the
maximum
number
of
RSS
processors
and
the
number
of
RSS
queues
to
be
equal
to
the
number
of
CPU
cores
In
multi
‐
port
scenarios
give
each
port
its
own
set
of
RSS
processors,
using
the
base
and
max
processor
settings
to
restrict
RSS
to
a
subset
of
the
CPUs
if
required.
•
For
other
applications
use
as
few
RSS
processors
as
required
to
cope
with
the
traffic
load,
leaving
other
CPUs
free
for
other
tasks