Specifications

21
Technology Overview
Xserve
Industry-Leading Storage
Flexibility
Large databases, digital video footage, immense scientific data sets, and uncom-
pressed video all place enormous demands on server storage resources. Addressing
these growing requirements by providing an industry-leading capacity of up to 2.25TB
of affordable internal storage,
1
Xserve offers characteristic storage performance and
flexibility with three drive bays accepting hot-plug Apple Drive Modules. Like Xserve
G5, the new Xserve offers SATA (Serial ATA) support, but upgraded to include the latest
SATA hard drives—with increased performance, capacity, and value. And now Xserve
supports SAS (Serial Attached SCSI) hard drives for the highest performance and most
demanding applications.
With each Apple Drive Module on an independent drive channel and connected to a
3Gb/s storage controller, the Xserve storage subsystem scales without compromising
performance. This unique architecture delivers the best balance of performance,
reliability, capacity, and price.
SATA Drive Technology
Xserve makes significant advances in built-in server storage with features such as a
sophisticated 3Gb/s SATA/SAS storage controller with a dedicated bus to each Apple
Drive Module. Xserve continues to deliver incredible internal storage capacity and
value, now supporting up to 2.25TB using new 7200-rpm 750GB Apple Drive Modules
that employ state-of-the-art perpendicular recording technology.
Every SATA drive in Xserve is rated 24/7 server class for reliability and performance.
The independent drive architecture in Xserve isolates the drives electrically, preventing
a single drive failure from causing unavailability or performance degradation of the
surviving drives—a common problem with multidrive parallel SCSI implementations.
The end result is a storage architecture that provides tremendous throughput and
excellent storage scalability.
SAS Drive Technology
Serial Attached SCSI storage, the next generation of SCSI technology, is designed for
the most demanding storage applications. Providing higher sequential performance—
over 126MB/s with 3.5-ms seek time—and far higher random performance than SATA
drives, the new SAS capabilities are nothing short of phenomenal.
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The 15,000-rpm Apple SAS drives provide the highest storage performance available
today. Rated enterprise class, they have best-in-class MTBF (mean time between
failures) ratings. That means you can trust Xserve to deliver ultimate reliability for
critical server environments and applications like email and database serving.
0 to 750 with perpendicular recording
The “bits” that constitute data have typically
been recorded end to end, or longitudinally
in a single plane on the surface of a hard
drive’s recording platter. The new 750GB
SATA drives offered with Xserve use state-of-
the-art perpendicular recording technology
to stack the bits vertically and in multiple
planes, thereby achieving much greater
capacity in a given area. Xserve accommo-
dates three such drive modules to provide
an astounding amount of internal storage
capacity in a 1U form—up to 2.25TB.
SATA and SAS drive technologies
For internal storage, Xserve offers both SATA
(Serial ATA) and SAS (Serial Attached SCSI)
drive technologies. Very reliable and delivering
great performance, SATA is the best choice
when high capacity and cost per gigabyte
are of primary and equal importance. When
the ultimate in performance and reliability is
required, SAS is the best choice, providing the
industry’s highest reliability and performance
for high-workload data.