A highly available and expandable, rack-dense, 1U dual-socket SMP server, for application
serving in Web environments
Please see the Legal Information section for important notices and information.
6
Disk Controllers
All SAS-equipped x3550 models include an integrated
Adaptec AIC9580W
Serial-Attach SCSI
(SAS)
controller. This controller supports up to
four
internal SAS LVD (low-voltage differential)
drives. SATA models have a separate SATA controller, which supports up to two internal SATA
drives.
The integrated
ServeRAID-8k-l
controller offers
hardware
RAID-0
/
1/10
support and
32MB
of fast
PC2-4200
DDR2
cache for the SAS drives. The
ServeRAID-8k
option adds
three
additional
RAID levels,
RAID-1E, 5
and
6
, along with
256MB
of cache memory for higher performance, and
battery backup,
without
consuming a valuable adapter slot.
The
SAS
controller provides data transfer speeds of up to
300MB
per second
5
in
each
direction
(
full-duplex
) across the SAS bus, for an aggregate speed of
600MBps
, nearly double that of
Ultra320 SCSI’s
320MBps
(half-duplex) bandwidth. The serial design of the SAS bus allows
maximum performance to be maintained as additional drives are added.
The
SATA
controller integrated in the SATA models supports up to
two
internal SATA II drives,
with maximum data transfer rates of up to
300MB
(half-duplex) per second. This is throughput is
similar to that of Ultra320 SCSI (
320MBps
, half-duplex). The SATA models also include firmware
support for
RAID-0/1
. The system can be upgraded to
hardware
-based
RAID-0/1/10/1E/5/6
for
higher performance, using the same IBM
ServeRAID-8k SAS/SATA
controller as the hot-swap
server models.
For external storage, the
MegaRAID 8480
controller enables connection to up to
four
IBM
System Storage
EXP3000
SAS expansion units (
48
HDDs total). It provides
RAID-0/1/10/5/50
support and
256MB
of onboard cache.
Additional external storage is available using one of several supported direct-attach, iSCSI or
SAN controllers.
Large HDD Storage Capacity
The x3550 offers a choice of disk storage, supporting up to
two
(
3.5
-inch) or
four
(
2.5
-inch)
hot-
swap
high-performance
SAS
drives, or
two
(
3.5
-inch)
simple-swap SATA
drives:
3.5-inch SAS
•
15,000
RPMs — 73.4,
146.8
or
300GB
(
600GB maximum
)
2.5-inch SAS
•
10,000
RPMs — 73.4 or
146.8GB
(
587.2GB
)
•
15,000
RPMs —
73.4GB (293.6GB)
3.5-inch SATA
•
7,200
RPMs — 160, 250, 500, 750GB or
1TB
(
2.0TB
)
2-5-inch drives not only require less space than 3.5-inch drives, they
weigh less, consume half
the power, produce less noise, seek faster,
and offer
increased reliability
.
Simple-swap SATA drives are
not
hot-swappable (the system must first be powered off);
however, no tools or jumpers are required for installation and removal, allowing for faster, simpler
servicing than fixed drives.
The hot-swap SAS drives use the Converged Tray for
interchangeability with other IBM System x
™
systems. If you need more storage space, terabyte
capacities are possible with external direct-attach, NAS and SAN solutions.
High-Performance Adapter Slots
The x3550 provides
two x8
(“by 8”)
4GBps
PCI-E (PCI Express)
adapters standard. Each is
capable of supporting
x1/x4/x8
adapters at full speed.
Both slots are
half-length/full-height
. If
desired, the riser card containing slot
2
may optionally be replaced with one that provides
one
half-length/full-height
(1GBps)
133MHz PCI-X
slot instead.
PCI-Express
is a high-performance, low-latency, next-generation serial I/O bus that is rapidly
replacing the older parallel PCI and PCI-X buses. A
x8
PCI-E adapter offers approximately
four
times
the maximum throughput of a 133MHz PCI-X adapter
6
. (A
x1
adapter offers throughput
similar to a
66MHz
PCI-X slot.)
Because the
SAS
,
ServeRAID-8k
and
8k-l
, dual
Gigabit Ethernet
,
systems management
and
video
controllers are integrated onto the system board, the two adapter slots are both
available
,
which offers a wide degree of latitude in expansion options.
5
Data transfer rates depend on many factors and are often less than the maximum possible.
