Who says the Itanium 2 processor is dead? Certainly not HP, which has introduced a strong dual-processor server, the Integrity rx1620-2, into its enterprise line-up. HP, a co-inventor and long-time supporter of the processor, has done a fine job with the server, using a less-expensive version of the chip to keep costs down and leveraging much of its mass-market engineering capabilities from its ProLiant systems to provide solid management and respectable high-availability and scalability features.

The Itanium 2 processor may not be sexy or have mass-market appeal, but Intel's 64-bit processor plays a significant role in high-performance computing. The processor's strength is that it drives massively scalable servers far beyond the capabilities of today's x86 processors, and its RISC architecture is clean and efficient, particularly for multi-threaded database processing, transactions systems, and floating-point math applications such as simulation, modelling, and BI.

Considering that Intel laid out an aggressive road map for the Itanium family at its Developer Forum in March, the processor architecture certainly seems like a safe bet. And if you're looking at Itanium 2 on a tight budget, the Integrity rx1620-2, although not perfectly equipped, is a safe bet for an entry-level server.

Less cache, less cost
The 1U rack-mounted Integrity rx1620-2 is similar to other dual-processor entry-level servers such as HP's Xeon-based equivalent, the ProLiant DL360 G4. The Integrity system supports one or two Itanium processors, both part of the family code-named Fanwood by Intel. These chips, available at 1.3GHz and 1.6GHz, were initially targeted at high-end engineering workstations, not servers. As such, they don't scale beyond two-way multiprocessing, which is unsuitable for bigger servers but ideal for this type of server.

The system HP provided had two 1.6GHz processors with a dual-channel bus that handles 533 mtps (millions of transfers per second). That corresponds to a 267MHz front-side bus. (Although that's slower than the 800MHz front-side bus on a high-end Xeon system, those numbers aren't directly comparable.) The dual-channel design of the memory bus, implemented by HP's own zx1 chip set, means that the system performs two separate memory operations per clock tick, each from its own memory bank. It's an efficient design for this architecture.

The Fanwood processors used in this server also contain 3MB of on-chip cache, essential for feeding the instruction bundles that are part of the Itanium 2 architecture. (The slower 1.3GHz processors also have 3MB of cache.) Unfortunately, that's the best this server offers, and it falls short of state of the art. For example, Intel's higher-end Madison family of Itanium 2 processors comes with 4MB, 6MB, or 9MB of on-chip cache. HP's rx2620 server, which is a 2U, four-drive version of the rx1620, supports the much costlier 6MB-cache chips. Other HP models use the 9MB-cache processors.

IBM and Sun have also stolen a march on the single-core Itanium 2. Sun's UltraSparc IV and IBM's Power5 chips, which are architecturally comparable to the Itanium 2, are shipping in dual-core versions today. So although the Fanwood processors let HP keep the price down and present an entry-level offering, the rx1620-2's per-chip performance lags behind other RISC systems.

One of the benefits of using the Itanium 2 processor family is that it supports large amounts of system memory. The rx1620-2 has eight PC2100 ECC memory sockets, which currently handle a maximum of 16GB RAM. This low ceiling is disappointing; other Itanium 2 servers, such as HP's own Integrity rx-7620-16, support as much as 128GB RAM. Give me memory! According to HP's product manager, the company originally intended the machine to support as much as 24GB RAM, but HP didn't find enough demand for this in its customer research.

Integrity infrastructure

Moving beyond the chip, the rx1620-2 is, again, similar to other dual-processor servers. It contains a dual-channel Ultra320 SCSI controller, with one channel feeding the two hot-swap drives and the other configured with an external connector for a separate disk enclosure. There are two integrated Gigabit Ethernet NICs.

For fans of HP's excellent server management systems, the Integrity rx1620-2 won't disappoint. The server contains an integrated management computer with its own network connection. The computer is similar to the ProLiant's iLO (Integrated Lights-Out) processor, with a seemingly identical serial, Telnet, and Web-based console, yet according to an HP product manager, they're built on different chips. The server processor has its own network connection. For fans of HP's excellent server management systems, the Integrity rx1620-2 won't disappoint.

A minor disappointment is in server I/O. A 64-bit server should be a transaction and networking workhorse, yet the I/O capabilities of the Integrity rx1620-2 are limited to two 64-bit, 133MHz PCI-X (PCI-Extended) slots, with a rated bandwidth of 1Gbit/sec. per slot. That's frankly inadequate, especially for use on modern FC (Fibre Channel) SANs, whose performance now reaches 4Gbit/sec. Where's PCI Express? According to HP, its chip set doesn't support it yet. That's a shame.

One area where HP earns mixed scores is in high-availability functionality. I'm impressed with the server's dynamic fault management: the server can detect a problem with a processor or memory chip and disable that chip upon an automatic reboot. It also reallocates memory pages dynamically without a reboot. That's the type of capability I'd expect in this type of enterprise server.

The server needs hot-swap power, like the dual-power offered in the ProLiant DL360 G4. I also wish it were easier to remove and replace. It's user-serviceable, but only barely so. If you blow a power supply or suspect a power problem, you'll probably be making a service call.

Overall, the Integrity rx1620-2 would fit well in a data centre standardising on the Itanium 2 processor. By anchoring the entry-level position, it would allow organisations to deploy relatively inexpensive dual-processor servers in clusters or run the same binaries on a range of machines based on the same architecture. Although imperfect -- and unfortunately constrained in cache, memory, and I/O -- the server is well suited to the entry-level market and small-scale applications.


This entry-level server offers an attractively low price for a dual-processor, Itanium 2-based server, and thanks to strong management it's well-suited for many data centres and clustering applications. The server suffers, however, by having limited memory capacity, and I/O bandwidth with PCI-X. It's also a shame HP doesn't offer the server with higher-cache versions of the Itanium 2 processor.