Serious scalability in a quad-Xeon server

I recently tested Compaq's ProLiant 6000 with the Pentium II Xeon Processor, the server that marks Compaq's entry into the quad-Xeon market. The system I reviewed includes four 400MHz Pentium II Xeon (Deschutes Slot 2 architecture) processors.

When I received the ProLiant 6000, the first thing I wanted to do was see the Xeon processor. To satisfy my curiosity, I removed one of the system's chips. It slid out easily and was soon in my hands.

Compaq Xeon 6000

The first time I saw a Pentium II, processors stopped looking like chips to me and started looking like field replaceable units (FRUs in IBM terminology) from mainframe-class systems. I've spent my share of time in shops with liquid-cooled mainframes, but I never thought I'd see a liquid-cooled PC processor. Compaq ships each Pentium II Xeon processor with what looks like a small radiator, a mechanism that transfers heat away from the chip's primary heat sink. Compaq calls this device the evaporator plate and water-cooled heat pipe. The mechanism lends a lower profile to the system board than the standard heat sink.

Replacing the ProLiant 6000's processor was easy. Compaq's processor-insertion guides make the process almost foolproof.

System Hardware
A ProLiant 6000 with four Pentium II Xeon processors supplies a fair amount of processing power, and the system has the I/O capacity and expansion capabilities to help you harness the processors' power. The ProLiant 6000's standard configuration includes one hot-swappable hard disk cage, but you can add two more cages. Each of the machine's cages can hold up to six 1" hard disks or up to four 1.6" hard disks. These numbers mean that if you configure the system with three cages and fill each cage with 9GB hard disks, you can store 162GB of data in a unit the size of a two-drawer filing cabinet. A couple years ago, I would have wondered what kind of network would ever need that much storage, but if you use online analytical processing (OLAP) databases and support users who rarely delete files, you'll appreciate the option to expand to 162GB. In addition to the hot-swappable hard disk cages, the system has six half-height 5.25" drive bays. One bay holds a 5.25" disk drive, one holds the system's CD-ROM drive, and four are empty.

The ProLiant 6000 has three Ultra Wide SCSI-3 buses that support data rates up to 40MBps. The system I tested includes Compaq's Smart Array 3100ES Controller, a 64-bit PCI card that has extended SCSI connectors that connect to each of the hot-swappable hard disk cages. With these connectors, the system doesn't require SCSI cables to the array controller. This feature makes for a clean installation and eliminates the need to remove cables when you remove the array controller. The ProLiant 6000 has 56MB of onboard, battery-backed, read-write cache that enhances the disk array's performance. The array supports RAID 0 (data striping with no fault tolerance), RAID 1 (mirroring), RAID 0+1 (a mirrored RAID 0 stripe set), RAID 4 (fault tolerance with a dedicated parity drive), and RAID 5 (fault tolerance with parity information spread across all drives). (For more information about RAID, see Joel Sloss, "RAID: Enhanced Disk Storage for Windows NT," August 1997.)

Three PCI buses with a total of ten I/O expansion slots give the ProLiant 6000 plenty of expansion capacity. Bus 1 and bus 2 each hold two 32-bit slots. Bus 3 holds five 64-bit slots, two of which include the extended SCSI connectors. Compaq designed the system's one ISA slot to hold a modem board. The system has a standard set of I/O interfaces. The integrated PCI video controller comes standard with 2MB of memory and supports resolutions up to 1024 * 768 pixels. The standard configuration also includes two serial ports and a parallel port. The keyboard and mouse ports use small PS/2 connectors.

The system supports Error-Correcting Code (ECC) RAM. It uses 60 nanosecond (ns) Enhanced Data Output (EDO) DIMMs up to 256MB each. Eight banks of four DIMMs in matched sets support a total of up to 8GB of memory.

Compaq supplies a Netelligent Dual 10/100 TX PCI UTP Ethernet controller and Compaq Advanced Network Control Utility software. You use the software to configure the Netelligent Ethernet cards; when you use it with a pair of dual-port or single-port Ethernet cards, the utility lets you set up fault-tolerant network connections. The ProLiant 6000 also comes with fault-tolerant power configurations. You can configure the server with as many as three load-balancing, hot-pluggable, redundant power supplies. Depending on your system configuration's power load, you might require two power supplies for system operation and a third power supply for fail-safe redundancy.

Management Software
Compaq ships the ProLiant 6000 with several systems management support utilities, including Compaq Insight Manager, Compaq Integrated Management Log Viewer, Compaq Array Configuration Utility, Compaq Power Down Manager, and Compaq Power Supply Viewer. These systems management features let the ProLiant 6000 work with any enterprise systems management product.

Companies that make the effort to engineer their products for reliability and easy detection of problems always impress me. For years, Compaq has been going a step further, providing features that predict potential component failures before problems occur. Compaq Insight Manager provides this functionality by monitoring key aspects of component performance. For example, the software monitors the length of time hard disks take to spin up. When spin-up time starts to take longer than usual, Compaq Insight Manager alerts users that the drive might be failing. Compaq supports the ProLiant 6000 with a 3-year onsite warranty, which includes prefailure replacement of processors, memory, and hard disks when Insight Manager reports a degraded component.

Compaq Integrated Management Log Viewer displays the system-level hardware event log that the ProLiant 6000 maintains. Compaq Array Configuration Utility displays configuration information about the Smart Array 3100ES Controller and lets you configure the controller. The utility is also a convenient tool for displaying information about your SCSI devices and device IDs.

Compaq Power Down Manager lets you disable the ProLiant 6000's external power switch or set the external power switch to shut down NT before powering down the system. Compaq Power Supply Viewer saves you from wondering whether your redundant power supplies are truly redundant. The utility displays power consumption as a percentage of available power, and it lets you know whether the server would survive a failure of one of your power supplies. Compaq Power Supply Viewer also displays AC line and DC output voltage levels.

How Does It Perform?
Because server vendors are increasingly standardizing computers' components, you can often attribute performance differences between systems that contain the same class of processor to I/O subsystem performance. When I ran the Windows NT Magazine Lab's usual file-server benchmark tests on the ProLiant 6000, I didn't expect results dramatically different from my recent benchmarks of HP's NetServer LH 3, a dual-450MHz Pentium II (Deschutes Slot 1) system. (For more information about the system, see "NetServer LH 3," December 1998.) The LH 3 has five disk spindles on a caching controller, and the ProLiant 6000 has only three disk spindles in its RAID 0 data array. Nevertheless, the ProLiant 6000 performed much better than the LH 3. I ran Bluecurve's Dynameasure Copy All Bi-directional tests with a Special File workload and a 24MB test data set to measure both systems' performance. The ProLiant 6000 peaked at 17,097KBps, almost 50 percent more throughput than the dual-processor system produced.

During the peak period of the ProLiant 6000 benchmark test in which I recorded 17,097KBps of throughput, the four processors' average CPU utilization was 58 percent, 53 percent, 47 percent, and 20 percent, for an average utilization of 45 percent. Because of these processor loads, I figured that removing one or two processors from the ProLiant 6000 would affect performance only minimally. To test my theory, I rebooted the server in a two-processor configuration, then ran the Dynameasure benchmark again. The ProLiant 6000's peak throughput dropped by only 8.6 percent--­throughput reached 15,629KBps, with an average CPU utilization of 66 percent. This test led me to the conclusion that the file-server application that the Dynameasure test simulates doesn't benefit much from a four-processor ProLiant 6000 unless you increase the disk subsystem's throughput capacity.

You'd probably like a performance improvement of more than 10 percent for an investment in 100 percent more processors. However, if you invest in a quad-Xeon system to run only a file-server application, you'll probably also invest in an I/O subsystem that better matches throughput capacity to the system's CPU capacity. Alternatively, you might invest in a quad-Xeon system to run back-office applications that are more CPU intensive than file-server applications and benefit more from the ProLiant 6000's four processors.

Is It for You?
The quad-Xeon ProLiant 6000 is a solid server with substantial expansion capacity. The system might work very well for a small business. The business could start with Model 1-128, a single-processor unit with a modest 128MB of RAM and standard SCSI controllers. Then, if the company needed more power, the ProLiant 6000 could grow to hold four Xeon processors, 8GB of RAM, and three SCSI channels or a fibre channel to support its RAID arrays.


ProLiant 6000 with the Pentium II Xeon Processor
Contact:
Compaq * 800-345-1518
Web: http://www.compaq.com
Price: $53,190
System Configuration:
Four 400MHz Pentium II Xeon (Deschutes Slot 2
architecture) processors, 512KB of Level 2 cache, 2.75GB of 60 nanosecond Enhanced Data Output RAM, Four 9.1GB 10,000rpm hard disks, Netelligent Dual 10/100 TX PCI UTP Ethernet adapter, Smart Array 3100ES Controller