Solarflare
Server
Adapter
User
Guide
Solarflare
Adapters
on
VMware
Issue
20
©
Solarflare
Communications
2017
287
On
some
server
motherboards,
choice
of
PCIe
slot
is
important.
This
is
because
some
slots
(including
ones
that
are
physically
x8
or
x16
lanes)
may
only
electrically
support
x4
lanes.
In
x4
lane
slots,
Solarflare
PCIe
adapters
will
continue
to
operate,
but
not
at
full
speed.
The
Solarflare
driver
will
warn
you
if
it
detects
the
adapter
is
plugged
into
a
PCIe
slot
which
electrically
has
fewer
than
x8
lanes.
For
SFN5000
series
adapters,
which
require
a
PCIe
Gen.
2
slot
for
optimal
operation,
a
warning
will
be
given
if
they
are
installed
in
a
PCIe
Gen.
1
slot.
Warning
messages
can
be
viewed
in
dmesg
from
/var/log/messages
.
Memory
bandwidth
Many
chipsets/CPUs
use
multiple
channels
to
access
main
system
memory.
Maximum
memory
performance
is
only
achieved
when
the
server
can
make
use
of
all
channels
simultaneously.
This
should
be
taken
into
account
when
selecting
the
number
of
DIMMs
to
populate
in
the
server.
Consult
your
motherboard
documentation
for
details.
Intel®
QuickData
Intel®
QuickData
Technology
allows
VMware
ESX
to
data
copy
by
the
chipset
instead
of
the
CPU,
to
move
data
more
efficiently
through
the
server
and
provide
fast,
scalable,
and
reliable
throughput.
I/O
AT
can
be
enabled
on
the
host
and
on
guest
operating
systems.
For
advice
on
enabling
I/OAT
in
the
guest,
consult
the
relevant
Solarflare
section
for
that
guest,
or
the
documentation
for
the
guest
operating
system.
I/OAT
must
be
enabled
on
the
host
if
it
is
to
be
used
in
the
guests.
To
enable
I/OAT
on
the
VMware
ESX
host:
On
some
systems
the
hardware
associated
with
I/OAT
must
first
be
enabled
in
the
BIOS
Log
in
to
the
ConsoleOS
on
the
VMware
ESX
host,
and
enter:
#
esxcfg
‐
advcfg
‐
s
1
/Net/TcpipUseIoat
Reboot
the
VMware
ESX
host
To
verify
I/OAT
is
enabled,
from
the
ConsoleOS
enter:
#
vmkload_mod
‐
l
|
grep
‐
i
ioat
NOTE:
The
following
VMware
KB
article
should
be
read
when
enabling
I/OAT: