Alpha/Linux Wiki

The Wildfire systems are large 21264 SMP servers built from "quads", also called quad building blocks, with up to eight quads in the largest configuration. ¹⁾

• Four 21264A or 21264C CPUs and up to eight PCI buses per quad, up to eight quads in the largest configuration ²⁾
• Two quad building blocks (QBBs) are paired back to back in a system box. A GS160 cabinet holds up to two system boxes and so 16 CPU modules; a GS320 adds a second cabinet for four boxes and 32 CPU modules. The GS80 is a rack system with up to two QBB drawers of four CPUs each, so eight CPUs in all. The three share the same switch technology and the same CPU, memory, and power modules. ³⁾
• QBBs are joined by the global port and distribution board; in a two-box system a hierarchical switch takes the place of that interconnect. I/O riser modules cable the QBB backplane to the PCI boxes, and a QBB supports up to two PCI boxes, one per I/O port on the local riser. ⁴⁾
• A memory module has eight DIMM slots in two arrays, and the interleave follows how the arrays are filled: 4-way for one module with one array populated, 8-way for two modules with one array each, 16-way for four modules with one array each, and 32-way for four modules with both arrays populated. Larger interleave performs better, and mixing memory sizes limits interleaving and bandwidth. ⁵⁾
• Systems can be split into hard partitions, each with its own System Control Manager and its own instance of the operating system ⁶⁾
• The firmware also offers soft partitions, set up by SRM environment variables (lp_count and friends) and started with lpinit, but only OpenVMS supports them. CPU and memory can be shared between soft partitions, but I/O is bound to a single partition. ⁷⁾

Use the final SRM version, V7.3-1 (see final SRM versions).

• The SRM console runs on COM1, whose default speed on these systems is 57600 baud rather than the usual 9600; the com1_baud variable changes it. ⁸⁾ A Linux serial console therefore needs a matching speed, e.g. console=ttyS0,57600; see Using SRM.
• Esc Esc scm switches from the console to the System Control Manager, and quit returns to COM1. From a VGA console, SCM commands are given at the SRM prompt as scm followed by the command. ⁹⁾

Current kernels include Wildfire support (CONFIG_ALPHA_WILDFIRE, or a generic kernel), ¹⁰⁾ booted from SRM with aboot, but no one has reported booting a kernel newer than the 2.6 series. The SRM console occupies the low memory that other Alphas leave to the kernel, ¹¹⁾ so a generic kernel must be built with CONFIG_ALPHA_LEGACY_START_ADDRESS turned off; with it on, as in the default configuration, the kernel leaves out Wildfire support entirely (see Kernel). ¹²⁾

The last reports are Linux 2.4 on all 16 processors of a GS160 in 2000 ¹³⁾ and Linux 2.6.17 on a 32-CPU GS320 in 2006, which nearly worked apart from a lost IRQ 4. ¹⁴⁾ In 2007 the same user reported that the GS320 had run CentOS, but needed a kernel.org kernel rather than CentOS's own, and had since been powered off. ¹⁵⁾ The mailing list archives hold no later report.

• Console: the serial consoles of GS160 systems connect to a terminal server in the cabinet, reached by telnet; the Windows NT PC delivered for console access is not required. ¹⁶⁾
• Power supplies: although each QBB has redundant power supply modules, losing one in any QBB takes down the whole GS160 or GS320. ¹⁷⁾
• Power: the GS80 runs from single-phase power, 2600 VA with one drawer and 3900 VA with two. ¹⁸⁾ The GS160 and GS320 need three-phase power, and a fully loaded system draws from 4,360 W (GS160 with one system box) to 11,900 W (GS320 with four system boxes). ¹⁹⁾
• Weight: fully configured, a GS80 weighs 260 kg (575 lb), a GS160 517 to 603 kg (1,140 to 1,330 lb), and a GS320 897 to 983 kg (1,978 to 2,168 lb). ²⁰⁾

Wildfire succeeded the AlphaServer 8200 and 8400, with the first systems, limited to four quads, due in March 2000. ²¹⁾

The following sources conflict with each other or with the account given above. They are listed here for further investigation.

• Wildfire model names
  • arch/alpha/Kconfig, Linux 6.10: "AlphaServer GS 40/80/160/320"
  • No HP document found mentions a GS40. Compaq's own user's guide covers only the GS80, GS160, and GS320. ²²⁾