Specifications

11
Technology Overview
Xserve
STREAM
The STREAM benchmark is a simple synthetic benchmark program that measures
sustainable memory bandwidth in megabytes per second (MB/s). It measures
sustained bandwidth, not burst or peak performance. Since the STREAM benchmark
is specifically designed to work with data sets that are much larger than the available
processor cache on any given system, the results are more indicative of the perfor-
mance of applications using very large data sets.
Massive memory bandwidth
Xserve delivers more than twice the memory bandwidth of Xserve G5.
Xserve
Four 1GB 667MHz DDR2
FB-DIMMs
Xserve G5
Four 1GB 400MHz DDR1
DIMMs
2.1x
Baseline
Testing conducted by Apple in October 2006 using preproduction quad 3.0GHz Xeon-based Xserve units; Xserve G5 systems were shipping units.
All systems were configured with 4GB of RAM. Results are based on the STREAM v. 5.6 benchmark (www.cs.virginia.edu/stream/ref.html) using
OMP support for multiprocessor-compiled builds and optimized for ICC (for quad Xeon-based Xserve) or XLC (for Xserve G5). Performance tests
are conducted using specific computer systems and reflect the approximate performance of Xserve.
Storage Performance
While processor performance is a critical factor in scientific applications, most server
workloads require a balance of processor, memory, disk, and network operations
to deliver outstanding overall performance. Xserve delivers significantly upgraded
storage capabilities compared with Xserve G5 by using a 3Gb/s-per-channel storage
controller that supports both SATA (Serial ATA) and SAS (Serial Attached SCSI) hard
drives. When configured with SATA drives, Xserve delivers tremendous value with
excellent storage performance. When configured with 15,000-rpm SAS drives—the
fastest and most reliable currently available in the industry—Xserve delivers maximum
performance with ultrafast seek times for demanding applications.
Iometer
Iometer is an I/O performance analysis tool for servers that was originally developed
by Intel and later released as an open source benchmarking tool. It measures system
I/O performance—throughput as well as latency—while stressing the system with a
controlled server workload.
Outstanding storage performance
SATA drive
750GB 7200-rpm
SAS drive
300GB 15,000-rpm
76MB/s
126MB/s
Iometer megabytes per second
SATA drive
750GB 7200-rpm
SAS drive
300GB 15,000-rpm
8.0 ms
3.5 ms
Average seek time (shorter is better)
Testing conducted by Apple in October 2006 using preproduction quad 3.0GHz Xeon-based Xserve units. Testing was conducted using Iometer
2004.07.03 with a 30-second ramp-up, a 2-minute run duration, and a 512KB request size. Each system was configured as an OS + test disk
configuration, where the OS resides on a single dedicated drive, and Iometer tests are performed against the second drive. Drive average seek
time from published manufacturer specifications. Performance tests are conducted using specific computer systems and reflect the approximate
performance of Xserve.