Disk Controllers - IBM 79784AU Product Manual

A highly available and expandable, rack-dense, 1U dual-socket SMP server, for application
serving in Web environments
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Data transfer rates depend on many factors and are often less than the maximum possible.
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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
(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
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
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.
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systems. If you need more storage space, terabyte
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. (A x1 adapter offers throughput
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in each direction
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