Lenovo 3797 User Manual
Page 81
v
The
specifications
of
a
DDR3
DIMM
are
on
a
label
on
the
DIMM,
in
the
following
format.
ggg
eRxff-PC3-wwwwwm-aa-bb-cc
where:
ggg
is
the
total
capacity
of
the
DIMM
(for
example,
1GB,
2GB,
or
4GB)
e
is
the
number
of
ranks
1
=
single-rank
2
=
dual-rank
4
=
quad-rank
ff
is
the
device
organization
(bit
width)
4
=
x4
organization
(4
DQ
lines
per
SDRAM)
8
=
x8
organization
16
=
x16
organization
wwwww
is
the
DIMM
bandwidth,
in
MBps
6400
=
6.40
GBps
(PC3-800
SDRAMs,
8-byte
primary
data
bus)
8500
=
8.53
GBps
(PC3-1066
SDRAMs,
8-byte
primary
data
bus)
10600
=
10.66
GBps
(PC3-1333
SDRAMs,
8-byte
primary
data
bus)
12800
=
12.80
GBps
PC3-1600
SDRAMs,
8-byte
primary
data
bus)
m
is
the
DIMM
type
E
=
Unbuffered
DIMM
(UDIMM)
with
ECC
(x72-bit
module
data
bus)
R
=
Registered
DIMM
(RDIMM)
U
=
Unbuffered
DIMM
with
no
ECC
(x64-bit
primary
data
bus)
aa
is
the
CAS
latency,
in
clocks
at
maximum
operating
frequency
bb
is
the
JEDEC
SPD
Revision
Encoding
and
Additions
level
cc
is
the
reference
design
file
for
the
design
of
the
DIMM
d
is
the
revision
number
of
the
reference
design
of
the
DIMM
v
The
following
rules
apply
to
single-rank
and
dual-rank
DDR3
DIMM
speed
as
it
relates
to
the
number
of
DIMMs
in
a
channel:
–
When
you
install
1
DIMM
per
channel,
the
memory
runs
at
1333
MHz
–
When
you
install
2
DIMMs
per
channel,
the
memory
runs
at
1066
MHz
–
When
you
install
3
DIMMs
per
channel,
the
memory
runs
at
800
MHz
–
All
channels
in
a
server
run
at
the
fastest
common
frequency.
–
Mixing
registered
and
unbuffered
DIMMs
is
not
supported.
v
The
DIMM
options
that
are
available
for
the
server
are
1
GB,
2
GB,
4
GB,
and
8
GB
(when
available).
The
server
supports
a
minimum
of
1
GB
and
a
maximum
of
128
GB
of
system
memory.
For
32-bit
operating
systems
only:
Some
memory
is
reserved
for
various
system
resources
and
is
unavailable
to
the
operating
system.
The
amount
of
memory
that
is
reserved
for
system
resources
depends
on
the
operating
system,
the
configuration
of
the
server,
and
the
configured
PCI
devices.
v
A
minimum
of
one
DIMM
must
be
installed
for
each
microprocessor.
For
example,
you
must
install
a
minimum
of
two
DIMMs
if
the
server
has
two
microprocessors.
However,
to
improve
system
performance,
install
a
minimum
of
three
DIMMs
for
each
microprocessor.
v
The
maximum
operating
speed
of
the
server
is
determined
by
the
slowest
DIMM
in
the
server.
Chapter
5.
Installing
optional
devices
and
replacing
customer
replaceable
units
65