Challenge / Onyx



Challenge L deskside version.

The Challenge "family" was Silicon Graphics series of servers ranging from small workgroup servers up to big highend servers for database or data mining applications (and even supercomputers). They have been introduced in the middle of the 90s and were available as refurbished products until summer 2001 (not all, but a part of the systems).

Challenge S
The Challenge S is a single processor server that is based on the same architecture as the Indy workstation series.
Challenge M
The Challenge M is a single processor server that is based on the same architecture as the Indigo 2 workstation series. It was soon replaced by the Challenge DM systems so it might be a bit rare.
Challenge DM
The Challenge DM server was Silicon Graphics entry level system to the family of symmetric multiprocessing server. The system supports up to 4 CPUs and is actually a "crippled" Challenge L (i.e. reduced number of supported CPUs, not all CPU types available).
Challenge L
The Challenge L servers support up to 12 CPUs and comes in the deskside case, that is also used for the DM models.
Challenge XL
The Challenge XL series is the highend of the Challenge "family" and supports up to 36 processors in one machine. To provide space for the additional hardware this machine comes in one of the big "refrigerator-style" cases.
Challenge GR
The Challenge GR is a system that has slots configured to support RealityEngine or InfiniteReality graphics boards, but because of that has has fewer slots for CPU, I/O, and memory. GR is an abbrevatation for "Graphics Ready".

Onyx deskside version.

The Onyx series is the first post-4D series of graphics supercomputers made by Silicon Graphics and still today SGIs really big graphics machines carry "Onyx" in their names. Possible configurations are:

Onyx Deskside
Onyx with up to 4 processors and either RealityEngine 2 or InfiniteReality graphics option.
Onyx Rackmount
Onyx with up to 24 processors and either RealityEngine 2 or InfiniteReality graphics option.
Single Processor Onyx with InfiniteReality graphics option. No multiprocessor upgrades are available.
Single Processor Onyx with RealityEngine 2 graphics option. No multiprocessor upgrades are available.


Challenge / Onyx systems can be classified as MIMD SMP systems.

MIMD Multiple Instruction Multiple Data. This means multiple instructions can be passed at the same time to multiple groups of CPU and FPU.

SMP Symmetric MultiProcessing is a common form for MIMD systems. All CPUs are treated alike and can perform any task at any time (this is unlike to Master/Slave concepts) as they share a common view of the memory.

The following ASCII Art Diagram shows the basic concept of (Power)Challenge systems. All subsystems are implemented on special boards which are plugged into a backplane that builds the systems bus. "..." indicates that multiple boards of a given type may be installed.

   CPU        CPU
    |          |
    |    ...   |       
  Cache      Cache      
    |          |         
    |          |         
=============================================== System Bus (1.2 GB/s)
    |          |          |          |
    |    ...   |          |   ...    |
    |          |          |          |
  Memory     Memory      I/O        I/O 

The VME Bus and/or Graphics interface is provided by additional boards that attache to the IO subsystem.


1993, 1st half (approx.)
Challenge M, L and XL systems with R4400 processor introduced
1993, January
Onyx graphics workstations introduced
VTX and RealityEngine 2 Graphics announced
1994, July
Challenge S and DM with R4400 and R4600 (S model only) processor introduced
Power Onyx systems with MIPS R8000 processor introduced
RealityEngine 2 offered with Power Onyx systems
Extreme Graphics option offered for (Power) Onyx systems
1994, Summer
Power Challenge systems with R8000 processors introduced
1994, November
Power ChallengeARRAY announced
1995, January
Reality Station announced (includes support for a single R4400/200 processor and a RealityEngine 2)
1995, July
250 MHz R4400 processor introduced
90MHz R8000 processor announced
1996, January
InfiniteReality graphics subsystem introduced
Power Challenge systems with R10000 processors
"IRIS Failsafe" cluster options presented
1999, March
End of Production
2008, December
End of Service


Challenge / Onyx

CPU Board Processor Number Clockspeed Cache (d/i) Cache (2nd) Floating Point
IP19 R4400 1, 2 or 4 100 MHz 16KB / 16KB 1MB or 4MB R4000 onboard
IP19 R4400 1, 2 or 4 150 MHz 16kb / 16kb 1MB or 4MB R4000 onboard
IP19 R4400 1, 2 or 4 200 MHz 16kb / 16kb 1MB or 4MB R4000 onboard
IP19 R4400 1, 2 or 4 250 MHz 16kb / 16kb 1MB or 4MB R4000 onboard

Power Challenge / Onyx

CPU Board Processor Number Clockspeed Cache (d/i) Cache (2nd) Floating Point
IP21 R8000 1 or 2 75 MHz 16kb / 16kb 1MB R8000 onboard
IP21 R8000 1 or 2 90 MHz 16kb / 16kb 1MB R8000 onboard
IP25 R10000 1, 2 or 4 195 MHz 32KB / 32KB 1MB or 2MB R10010 onboard

Maximum Configuration

System Max. Boards Max. R4400 Max. R8000 Max. R10000
Challenge DM 1 4 2 4
Challenge L 3 12 6 12
Challenge XL 9 36 18 36
Onyx Deskside 1 4 2 4
Onyx Rackmount 6 24 12 24



MC3 memory board.

Memory is added to Challenge / Onyx systems on additional MC3 memory boards or additional memory kits on already existing MC3 boards. The following table shows the possible configuration of a single board. Deskside systems support only one MC3 board, rackmount Challenge / Onyx systems support up to 8 MC3 memory boards for a total of 16 GB memory.

Type:                   ECC protected
Sockets:                32 (8 * 4 sockets)

Minimum configuration:  64 MB (4 * 16 MB SIMMs)
Maximum configuration:  2048 MB (32 * 64 MB SIMMs) 


  • Challenge server systems
  • Extreme Graphics
  • VTX (see RealityEngine 2)
    VTX is a lower end configuration of the Reality Engine 2.
  • Reality Engine 2 (RealityEngine 2)
    The maximum number of Raster Mangers for all deskside systems (including Reality Station) is 4, the racks can support 12 with 3 RealityEngine 2 pipes.
  • InfiniteReality
    The maximum number of Raster Mangers for all deskside systems (including i-Station) is 2, the racks can support 10 with 3 InfiniteReality pipes.
    Not supported with IP21 / R8000 CPU.


IO4 Controller Board (POWERChannel 2 Interface Board)

IO4 board with mezzanine boards installed.

The IO4 I/O Controller implements the basic I/O functions for Challenge / Onyx systems:

  • Ethernet Controller
  • two fast/wide 16 bit SCSI-2 controllers
  • four serial ports (3x RS232, 1x RS422)
  • a parallel port
  • two Flat Cable Interfaces (for VME or Graphics)

In Challenge Deskside systems 3 IO4 controller boards can be installed, in rackmount Challenges up to 4 of these boards. In Onyx Deskside systems 1 IO4 controller can be installed, in rackmount Onyxes up to 6 of these boards.

System Controller

The system controller monitors various system data (fan speed, temperature, voltages) and can initiate a controlled shutdown if any of these values exceeds given ranges. It is battery-backed and records error messages in case of any unplanned shutdown of the system.

The system controller consists of a board which is installed on the back side of the backplane and a module on the front of the machine which includes the status display as well as the controls of the machine.

Power Subsystem

All Challenge and Onyx systems have an OnLine Switching powersupply (OLS) that generates 48V power from incoming 115V or 230V sources. This is distributed throughout the system and converted to other voltages where required.

The memory and processor boards have their own onboard power converters, for other subsystems power boards are attached to the back side of the backplane:

  • 512T power board provides 12V power to the IO4 and VMEbus
  • 505 power board provides 5V power which is required for RealityEngine2 graphics VMEbus
  • 303 power board provides 3.3V power for InfiniteReality graphics
  • 305 power board provides 3.3V power for InfiniteReality graphics and 5V power for VMEbus

For rackmount systems double width power boards are available.


IO Channels


HIO Options are connected directly to the IO4 board as mezzanine daughtercards. Among the common standard additions to the IO4 are the

  • VCAM
    VME Bus Interface. 5 VME Slots are supported per IO4/VCAM (appropriate back-/midplane required). The VCAM must be installed on the primary IO board and it attaches to the first VME slot (directly to the right of it).
  • GCAM
    Additional Graphics Interface for running an Extreme Graphics option in a VME Slot.
  • Mezzanine Options
    ASO Audio Serial Option
    SCSI (1st Generation controller)
    SCIP 2nd Generation fast/wide SCSI controller (2 differential, 1 differential or single ended)
    FCI Flat Cable Interface (connects remote VCAM)


VME Bus interfaces are provided by the VCAM mezzanine board. Any system can use 9U, 6U or 3U VME cards - for the smaller ones the appropriate adapter boards are required to plug the card into the 9U backplane connection. Options include:

  • Fore ATM
  • MCO Multi Channel Option
  • Sirius Video
  • Vigra Sound (press release)
  • FDDI
  • 100Base-T Ethernet

SCSI Vaults

Different external SCSI enclosures were available for the Challenge / Onyx systems. The Challenge Vault L is a large tower approximately of the same height as the Deskside chassis. The Challenge Vault XL has the same dimensions as a full rack and can be used to install up to 12 SCSI Box 2.


Deskside (Eveready)


The Challenge /Onyx come a chassis that looks like the PowerSeries single tower chassis. The dimensions are as follows:

width:     54 cm / 21"
height:    66 cm / 26"
depth:     74 cm / 29"

weight:    ? kg / ? lbs 

All Challenge Deskside systems have a gray case and a teal top hat / drive door. As there are no graphics options there is no color code but the type of CPU is specified on the machines ("10000" or "POWERchallenge"). All Onyxes are black and have a purple top hat and drive door.

Cardcage of a loaded Onyx. Drives on the right.

The Deskside chassis has room for 7 half height 5.25" devices on the right side of the cardcage. It is also possible to place 3 full-height and 1 half-height devices into the slots. All devices have to be mounted in the system with a custom drivesled available from SGI.

Challenge DM/L Setup

This table lists only the front slots where the main boards slide in. On the other side of the midplane power boards and the system controller are installed.

The Challenge DM is limited to only one CPU board by a screw that is on the backplane. This information had been around as around as a rumour for years, it has been verified in this forum thread.

Front Cardcage
01 EBUS #1: IP19, IP25, MC3 or IO4
02 EBUS #2: IP19, IP25, MC3 or IO4
03 EBUS #3: IP19, IP25, MC3 or IO4
04 EBUS #4: IP19, IP25, MC3 or IO4
05 EBUS #5: IP19, IP25, MC3 or IO4
06 VCAM VME interface
07 VME The VME Slots have to be filled from left (#7) to right (#12) with no empty slots in-between.
08 VME
09 VME
10 VME
11 VME
12 VME

Onyx Setup

This table lists only the front slots where the main boards slide in. On the other side of the midplane power boards and the system controller are installed.

Front Cardcage
01 EBUS MC3 memory board
02 EBUS CPU board (IP19, IP21 or IP25)
03 EBUS IO4 IO board
04 VCAM VME interface
05 VME The VME Slots have to be filled from left (#5) to right (#7) with no empty slots in-between.
06 VME
07 VME
08 GFX

The graphics slots need to be filled according to the slot assignment of the installed graphics option:
Reality Engine 2 or Infinite Reality

Note that these graphics options have different power requirements which require also a different power board setup!

09 GFX
10 GFX
11 GFX
12 GFX
13 GFX

Rackmount (Terminator)


The Challenge / Onyx rack is similar to the PowerSeries rack but it is a lot deeper. Integrated into the front door is the systems status display.

width:     69 cm / 27"
height:    159 cm / 62.3"
depth:     122 cm / 48"

weight:    254 kg / 560 lbs (miniumum)
           544 kg / 1200 lbs (maximum) 

The rack can be equipped with up to two cardcages (2x on the back and 1x on the front). The front side has additional space for drives and other devices.

Challenge XL Setup

Onyx Setup

Please note that Infinite Reality systems require a different midplane ("KONA ready") and a different set of power boards. Upgrading from Reality Engine 2 to Infinite Reality requires more then just a simple board swap - even if a KONA ready midplane is already present.

Cardcage 1 (front)
01 PWR Power board
02 PWR Power board
03 - unused
04 PWR Power board
05 SYS System Controller
06 EBUS #10: IP19, IP25 or MC3
07 EBUS #8: IP19, IP25 or MC3
08 EBUS #6: IP19, IP25 or MC3
09 EBUS #4: IP19, IP25 or MC3
10 EBUS #2: IP19, IP25 or MC3
Cardcage 2 (back)
01 EBUS #1: IP19, IP25, MC3 or IO4
02 EBUS #3: IP19, IP25, MC3 or IO4
03 EBUS #5: IP19, IP25, MC3 or IO4
04 EBUS #7: IP19, IP25, MC3 or IO4
05 EBUS #9: IP19, IP25, MC3 or IO4
06 EBUS #11: Master IO4
07 VCAM VME interface
08 VME The VME Slots have to be filled from left (#8) to right (#9) with no empty slots in-between.
09 VME
10 VME
11 GFX GE Gemometry Engine
12 GFX RM Raster Manager
13 GFX RM Raster Manager
14 GFX RM Raster Manager
15 GFX RM Raster Manager
16 GFX DG Display Generator
Cardcage 3 (back)
01 RVCAM VME interface (Remote VCAM)
02 VME The VME Slots have to be filled from left (#2) to right (#4) with no empty slots in-between.
03 VME
04 VME
05 GFX GE Gemometry Engine
06 GFX RM Raster Manager
07 GFX RM Raster Manager
08 GFX RM Raster Manager
09 GFX RM Raster Manager
10 GFX DG Display Generator
11 --- not used
12 RVCAM VME interface (Remote VCAM)
13 VME The VME Slots have to be filled from left (#13) to right (#15) with no empty slots in-between.
14 VME
15 VME
16 GFX GE Gemometry Engine
17 GFX RM Raster Manager
18 GFX RM Raster Manager
19 GFX RM Raster Manager
20 GFX RM Raster Manager
21 GFX DG Display Generator


PowerChallenge Array

The PowerChallenge Array was an attempt at providing a supercomputing system by integrating several PowerChallenge (either R8000 or R10000) systems into a larger Cluster/Array. The single systems, referenced as nodes, would still remain the shared memory systems they are and be connected using highspeed networks as HiPPi. Programs that scale beyond the capabilities of a single node need to share their data using Message Passing techniques. A technical report is available here.

PowerChallenge Webforce

Like other Silicon Graphics systems of the mid 1990s the Power Challenge DM, L and XL systems were available as a Webforce package. Part of this was the following software:

  • Netscape Enterprise server 2.0
  • Network File System (NFS) 3.0
  • PCP/WebMeter system monitoring software
  • Public Domain Software (Unsupported):
    Elm/Pine Mail Readers, POP3 Mail, WAIS, News Readers
    NCSA Mosaic Browser, and more
  • Cosmo Site Web site management software

The PowerChallenge Webforce brochure is available here.

Rebadged Challenges

Like a lot of SGI systems Challenge servers were also sold by other companies, Tandem and Control Data at the moment being the only ones known. The Tandem Challenge server are all completely black as is their Challenge S model. Instead of SGI logos the CDC systems have "Control Data 9000 Series" printed on them, otherwise they look the same as the SGI labeled Challenges.

Magic Edge / Namco Flight Simulator

This is an example of an Onyx being used in simulation - this time it only isn't scientific but more a very high end arcade game. System16 has some details on this machine driven by a Onyx RE2 with R4400 CPUs. The cost they list for the whole system is $750,000 in 1993 which probably explains why it wasn't a big success although the graphics capabilities of the systems were way ahead these days.


Battery Failure

Signs of failure: NVRAM values are messed up and no longer stored.

Like other SGI systems of this age the Challenge / Onyx systems do have a Dallas timekeeper installed which stores the NVRAM information. This chip is battery powered and is unable to recharge even if the machine is running. Sooner or later the power from this battery will be drained and the system will lose all stored NVRAM data.

The Dallas DS1397 timekeeper used on the IO4 board as well as the system controller board has to be hacked to be equipped with an external battery. Jan-Jaap van der Heijden does have pictures and a writeup on such a modification on a IO4 board on his website. Also there is a related Nekochan post which also covers the system controller board.


Powersupply replacement.

The older type of Challenge / Onyx powersupplies rated at 1500W (115V) or 1900W (230V) were replaced by SGI when the systems were still in support. The reason for the replacement had been mad public, it did include a potential fire hazard as well as health hazards.

In practice most of the systems still considered "in use" back then where probably upgraded. It might still be worth though to check on the PSUs in any of the Challenge / Onyx systems. More so if the system is left unobserved for longer times.


Nr Name Description
030-0223-00x DG2 RE Display Generator
030-0224-00x RM4 RE Raster Manager
030-0233-xx1 DI1 RE Edge Connector
030-0234-00x DI2 RE Edge Connector
030-0240-00x IO4 IO Board
030-0242-00x MEZ-F Mezzanine SCSI
030-0245-00x MC3 Memory Board
030-0250-00x IP19 4x 100MHz R4400
030-0310-00x Onyx Backplane Reality Engine
030-0311-00x DI3 RE Edge Connector
030-0325-00x GE10 RE Geometry Engine Onyx Reality Engine 2
030-0342-010 VO2 Sirius Video Board
030-0347-00x RM5 RE Raster Manager RE2 only
030-0359-00x RM4 RE Raster Manager
030-0360-00x RM4T RE Raster Manager
030-0363-00x GE10V RE Geometry Engine Onyx VTX only
030-0374-00x IP19 2x 150MHz R4400
030-0375-00x IP19 4x 150MHz R4400
030-0377-00x IO4 IO Board
030-0500-00x VCAM
030-0502-00x VCAM
030-0513-00x DG2 RE Display Generator
030-0536-00x GCAM
030-0555-00x Onyx Backplane (KONA ready) Infinite Reality
030-0604-00x MC3 Memory Board
030-0607-00x MC3 Memory Board
030-0613-00x MC3 Memory Board
030-0614-00x MC3 Memory Board
030-0625-00x IP21 2x 75 MHz R8000
030-0646-00x IO4B IO Board
030-0652-00x IP19 2x 200MHz R4400
030-0653-00x IP19 4x 200MHz R4400
030-0681-00x GE12 IR Geometry Engine
030-0683-00x RM6-16 IR Raster Manager
030-0684-00x RM6-64 IR Raster Manager
030-0686-00x DG4-2 IR Display Generator
030-0687-004 DG4-8 IR Display Generator
030-0702-00x IP21 2x 90 MHz R8000
030-0711-003 IR Frontplane
030-0720-00x IP19 1x 200MHz R4400
030-0751-00x IP21 1x 75 MHz R8000
030-0804-00x IP19 4x 250MHz R4400
030-0805-00x IP19 2x 250MHz R4400
030-0806-00x IP19 1x 250MHz R4400
030-0815-00x IO4 IO Board
030-1072-00x IP25 4x 195 MHz R10000
030-1107-00x IP25 2x 195 MHz R10000
9150800 Indigo Mouse
9500801 Indigo Keyboard


Onyx Reality Engine 2

Onyx deskside version.

Onyx front panel with standard connectors and Audio Serial Option (ASO).

Loaded Onyx with ASO, dual Fast Ethernet and Sirius Video.

Cardcage of loaded Onyx.

Cardcage of loaded Onyx.

Cardcage of a loaded Onyx.

Cardcage closed.

CPU Boards

IP19 CPU board (2x R4400).

IP21 CPU board (2x R8000/70 MHz).

IP25 CPU board (4x R10000/195 MHz).

IO Boards

IO4 board with mezzanine boards installed.

Memory Boards

MC3 memory board.

Option Boards

VO2 Sirius Video board.

Multi Channel Option board (VS2). 

Reality Engine 2

GE10 Geometry Engine (Reality Engine 2).

RM4 Raster Manager (Reality Engine 2).

Challenge L

Challenge L deskside version.

Challenge L deskside frontpanel.


Press Releases

  • 1994, July - New System Combines World's Leading Graphics with World's Leading Supercomputing Performance [local]
  • 1994, November - Company Continues to Reinvent Supercomputing with New Distributed
    Parallel Processing System [local]
  • 1995, January - Silicon Graphics cuts cost of world's fastest graphics with introduction of Reality Station [local]
  • unknown date - VigraSound version 1.0 now available [local]



  • An SGI catalogoue from approx. 1994 featuring pictures (DIN A4 fullsize) and short german descriptions of Indigo, Indigo 2, Crimson, Onyx, Challenge and Power Challenge: Page 1, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 (numbers refer to the original page number, not the filename; Scan by Ganjatron)
  • An SGI product guide featuring the Onyx, Reality Engine and Infinite Reality graphics. Page: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12

Technical Papers