HP N4000 (rp7400)
Overview
Project names
- N4000-36/rp7400: Prelude W
- N4000-44/rp7400: Prelude W 440
- N4000-5X/rp7400: Prelude W+ 550
- N4000-6X/rp7400: Prelude W2
- N4000-7X/rp7400: Prelude W2
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:
- A3639A apparently supported the 360MHz and 440MHz processors
- A3639B supports 360MHz, 440MHz and also the 550MHz PA-8600
- A3639C and A3639CD support 360MHz, 440MHz and 550MJz PA-8600 and 650MHz/750MHz PA-8700s
- A8327A supports 360MHz, 440MHz and 550MHz PA-8600 and 650MHz/750MHz PA-8700s
Processor types are indicated with the following suffixes:
- -36: PA-8500 360MHz with 512/1024KB on-chip I/D L1 cache each [A3639A, A3639B, A3639C, A8327A]
- -44: PA-8500 440MHz with 512/1024KB on-chip I/D L1 cache each [A3639A, A3639B, A3639C, A8327A]
- -5X: PA-8600 550MHz with 512/1024KB on-chip I/D L1 cache each [A3639B, A3639C, A8327A]
- -6X: PA-8700 650MHz with 768/1536KB on-chip I/D L1 cache each [A3639C, A8327A]
- -7X: PA-8700 750MHz with 768/1536KB on-chip I/D L1 cache each [A3639C, A8327A]
- Itanium 2/IA64 processors are probably also possible on some models [apparently never materialized]
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:
- 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
) - 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
- 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
- 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:
- Two HP Diva Serial [GSP] Multiport UARTs
- DEC 21142/43 Fast Ethernet controller (Tulip)
- Dual-channel Symbios Logic 53C875 16-bit Ultra-Wide SCSI-2 controllers
- Dual-channel Symbios Logic 53C896 Ultra2-Wide SCSI-3 controller
» 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.
- Two system buses, 133MHz, each 2.1GB/s peak — about 4.3GB/s aggregate (the system bus is in fact formally an Itanium/Merced system bus)
- Eight Runway CPU buses, each 2.1GB/s peak — aggregate 17.0GB/s peak (these Runway buses are attached to the two system buses — this means the CPUs have a theoretical bandwidth which cannot be sustained by the system’s main bus)
- Four Memory buses, each 2.1GB/s peak — aggregate 8.5GB/s (interestingly, the memory bus bandwidth is much wider than the CPUs’ maximum bus bandwidth, leaving room for anticipated CPU upgrades, which apparently never really materialized)
- 24 I/O data channels, each 133MHz 265MB/s — 6.4GB/s aggregate
- 14 PCI-64/66 I/O buses for expansion slots
- Three SCSI-3 Ultra2-Wide LVD main storage I/O buses, one for each internal drive and one for external devices
Memory
- ECC SDRAM DIMMs
- 16 slots
- 256MB, 512MB, 1GB and 2GB modules supported
- 32GB maximum
Expansion
- 10
Twin-Turbo
PCI 64-bit/66MHz slots, each on an independent PCI bus, each connected via two I/O links/ropes (aggregate 530MB/s), hot-plug capable - Two
Turbo
PCI 64-bit/66MHz slots, each on an independent PCI bus, each connected via one I/O link/rope (265MB/s), hot-plug capable (one of these two Turbo slots is reserved for Core I/O LAN/SCSI) - All slots keyed for 5.0V (support either 5.0V or universal PCI cards)
Drives
- Two internal Ultra SCSI LVD 3.5″ drives with SCA connector, hot-pluggable
- No internal removable devices etc.
External Connectors
- 68-pin VHDCI Ultra LVD external SCSI
- Three DB9 male RS232C serial (local console, remote console, general purpose) via a
DB25
M cable
- 10/100Mbit Ethernet TP/RJ45
- 10/100Mbit Ethernet TP/RJ45 LAN console
ROM update
There is an firmware update available which contains the latest version (43.43).
- PF_CPIW4343.txt has details about the contents and installation of the patch.
- PF_CPIW4343.tar.gz contains the patch.
References
- hp server rp7400 whitepaper, Hewlett-Packard Company (February 2002, product number 5981-0154EN) [did not find an appropriate URL for this PDF document —Ed.]
- rp7400 Hardware Manual (PDF) Hewlett-Packard Company (May 2002)
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
- Rack-mounted: 10U height
- Up to three power supplies — two are needed for the maximum configuration of CPUs, memory and drives, the third would be redundant