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HP N4000 (rp7400)

Overview

Project names

Introduced: 1999-2001

The rp7400 were the original version of the N4000 line of servers — the newer rp7405 and rp7410 servers were also labeled as N4000 and feature a similar set of I/O options and expandability in basically the same chassis. However the original N4000, the rp7400 described here, is based around a different system architecture than their sucessors — the Stretch chipset, also used in the L1500 and L3000 (rp5430/rp5470) servers.

The original N4000s were shipped in two models, with differences in their system board — A3639A and A3639B. The N4000 which was later renamed to rp7400 was shipped with an even different mainboard and had the model number A3639C. These individual system boards supported different processors etc.

Internals

CPU

The rp7400 N4000 supports one to eight processors.

There are several classes of possible processors, both shipped with the systems or later upgraded. Support for individual processors depends on the specific system with corresponding firmware revisions, operating system support and, lastly, the system’s support/auxiliary hardware (power supplies, voltage changers, etc.) and mainboard.

The original N4000 (A3639A and A3639B) and later rp7400 (A3639C) are in fact different products, based on the same basic architecture but with slight differences, especially relating to the type and number of processors. Not all early N4000s support the later processors and a maximum number of CPUs:

Processor types are indicated with the following suffixes:

Chipset

The rp7400’s system architecture is centered around the Stretch central electronic complex (chipset), also used in the L1500 and L3000 (rp5430/rp5470) servers. Stretch is based on four main components, to which the processing and I/O parts of the N4000 attach — the central memory controller, the Runway CPU port converters, the I/O controllers and the PCI bridges:

  1. Prelude SMC memory controller is the central part of the system, it connects the memory to two system buses, to which each one IKE I/O controller and two DEW Runway ports (for each two CPUs) attach (Prelude is also called Very Low Latency Memory Controller)
  2. Four DEW Runway ports/converters convert the Prelude’s system bus(es) (which in fact is an Itanium/Merced bus) into Runway buses for the up to eight CPUs — each two CPUs share one DEW port converter
  3. Two IKE I/O controllers attach each to one system bus on one side and to eight (left IKE — system bus 0) or six (right IKE — system bus 1) PCI bridges
  4. 14 Elroy PCI bridges (LBAs) which convert the I/O channels from the IKE I/O controllers into PCI buses, to which the PCI slots and core I/O functions attach

The remainder of the system I/O is made up of common parts, also found on other HP 9000 servers:

» View a system-level illustration (ASCII) of the N4000’s system/bus architecture.

Buses

The system bus architecture is in some ways rather strange, as it provided much more theoretical bandwidth than could be used under practical circumstances (witness the 17.0GB/s peak bandwidth of the CPUs versus the 4.3GB/s aggregate system bus bandwidth to which CPU, memory and I/O attach). The designers probably counted on future CPU upgrades, such as Itanium processors.

Memory

Expansion

Drives

External Connectors

ROM update

There is an firmware update available which contains the latest version (43.43).

References

Operating Systems

Benchmarks

Model SPEC2000, int SPEC2000, fp SPEC2000
rate, int		 SPEC2000
rate, fp
N4000-6X
rp7400		 493 489 5.7
2-CPU: 11.3
4-CPU: 22.1
8-CPU: 42.6		 5.7
2-CPU: 10.4
4-CPU: 19.3
8-CPU: 30.5
N4000-7X
rp7400		 551 524 6.4
2-CPU: 12.5
4-CPU: 24.6
8-CPU: 46.7		 6.1
2-CPU: 11.0
4-CPU: 20.5
8-CPU: 32.1

Compare these with other results on the Benchmarks page.

Physical dimensions

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