FAQABOSS: Frequently Asked Questions About Buying an Old (Used) Sun System

FAQ Status

This document is no longer under construction; I'm rewriting it and will soon release a new version (available for preview). Still, your help in compiling information, detecting errors, and promoting clarity is appreciated. Please address corrections and suggestions to brush@acomp.usf.edu. See the revision history for a list of changes.

Information in this document comes from James Birdsall's Sun Hardware Reference, from Brian Wong's Configuration and Capacity Planning for Solaris Servers, from personal experience, and from innumerable Usenet posts. Much material has also been provided by James Lockwood. Furthermore, he and many others have contributed valuable suggestions. This document is copyright (c) 1999-2001 Brian L. Brush. You may distribute it freely in unmodified form.

Who are you, and why are you qualified to write this FAQ?

I'm a Unix system administrator. Solaris is my specialty, and I work both as an employee and as a consultant. I worked at Academic Computing at the University of South Florida from October, 1994, until September, 1999. In those years, I helped move the department from a few low-end SPARCstations running SunOS 4.1.x to several mid-range Ultra Enterprise systems running Solaris 2.x. I'm now a system administrator at [company reference omitted due to instructions from on high]. For the gory details about me, check my C.V.

Why Buy a Sun?

This document is really intended for those who already want to buy one, but if you're still debating, I can mention some of my reasons. Many of them apply to the products of SGI, HP, IBM, and other Unix hardware vendors (and sometimes even Apple), as well.

• Well designed enclosures
• PROM monitors
• Support for serial consoles and multiple displays
• Tight integration of hardware and software

Background

FIXME

Sun 3s

The Sun 3 line used Motorola's 68020 and 68030 CISC microprocessors. See the Sun Hardware Reference and the Sun-3 Archive for more information.

SPARCstations

Most individuals in the market for used Suns will want SPARCstations, which use Sun's SPARC processors (except, of course, for the exceptions). They range from very cheap, very slow machines made a decade ago to very expensive SMP desktop machines of recent manufacture. First, some background:

Architecture

Sun uses the concepts of kernel architecture and application architecture to describe its systems. Every processor has an associated kernel architecture and application architecture.

The application architecture for all SPARC processors--and, therefore, for all SPARCstations--is sun4. Solaris's deprecated arch(1) command will show the application architecture. All SPARC processors will run binaries for the sun4 application architecture. Thus, the copy of ls(1) on your SPARCstation IPC will work on your SPARCcenter 2000E (you lucky devil!). Incidentally, Sun's Ultra line also uses the sun4 application architecture. One generally does not have to worry about the application architecture, because it hasn't changed for the last ten years.

The kernel architecture varies among SPARC processors. Both arch(1) and uname(1) will show the kernel architecture. Processors of different kernel architectures cannot use the same operating system kernel. Thus, you cannot boot your SPARCstation 20 with the same kernel that boots your SPARCstation IPC. The importance of kernel architecture is that Sun drops support for old kernel architectures in its O.S. For example, Solaris 2.4 was the last release that supported the sun4 kernel architecture (not to be confused with the sun4 application architecture). Here are some examples of machine families and their architectures:

Enclosures

A couple of the cases Sun used for workstations and peripherals have been given informal names. A lunchbox is literally the size and shape of a common plastic lunch box (but rather more difficult to open) and--in different incarnations--can hold a workstation or a bunch of disk drives. The common lunch box machines are the IPC and the IPX. A pizza box is literally the size and shape of a cardboard pizza box (but usually a bit thicker). There are several different pizza boxes of different designs and dimensions. The popular pizza box form factor was used for the SPARCstations 1, 2, 10, and 20, among others. See "Pictures of Sun Hardware" on SunHELP for images.

System Names

Sun has a penchant for renaming (and retroactively renaming) products: witness the renaming of SunOS 4.1.4 to Solaris 1.1.2, etc. Fortunately, it also likes to continue existing naming schemes for consistency. The earliest SPARC systems had names in the style of the Sun 3 systems: 4/110, 4/330, 4/600. With the debut of the SPARCstation 1, Sun introduced a new naming convention but continued, for a time, to assign the older-style names, as well. For example, a SPARCstation 1 is also a 4/60, and a SPARCstation 2 is a 4/75. The older machines were then officially renamed SPARCstation 330, and so on. This document will refer to the names used at the introduction of each product. Incidentally, Sun stopped assigning the older-style names around the introduction of the SPARCstation 10. By that time, it had other naming problems to worry about, such as the number and speed of the processors.

Operating Systems

I'm finally convinced of what Sun has been saying for a while now: Solaris is faster than SunOS in most aspects, but slower in many ways because of increased functionality. On the slowest machines, it's so slow it's nearly unusable, making the increased functionality a moot point. It also makes better use of RAM but requires more of it. Some older workstations have maximum RAM configurations that are just too low to make Solaris a reasonable proposition.

SunOS is just too old for most of us. Don't use it unless you have a good reason.

The free Unix operating systems that run on SPARC hardware--namely, Linux, NetBSD, and OpenBSD--are good alternatives for the older machines. They are lightweights compared with Solaris and are recent and well supported.

Solaris is a good option for newer machines (4 and up) equipped with enough RAM. It is particularly useful for providing robust SMP on the MP-capable desktop machines (namely, the 10 and 20).

Standard Equipment

Unless otherwise noted, all SPARCstations have some form of the following on their motherboards:

• SCSI controller
• ethernet adapter
• sound support
• serial ports
• SBus slot(s)

Some have parallel ports and on-board frame buffers; a few have more exotic additions like ISDN.

Now, after that interlude, some information on the SPARCstations:

AMD AM79C30A

"Telephone quality" audio chip capable of 8 KHz monaural audio input and output that supports mu-law and A-law but not linear encoding; found in sun4c systems and SPARCclassic.

T5900FC

DBRI (Dual Basic-Rate ISDN) chip for audio I/O that, in addition to audio, supports ISDN (dual B channels plus one D channel) but requires an NT1 in the US to connect to a line; found in LX, 10, and 20. Those systems require a CS4215 codec to generate and receive audio.

Crystal Semiconductor CS4215

Serial audio codec capable of up to 48KHz 16-bit stereo using mu-law, A-law or linear encoding. The 10 houses it in an external speaker box; the LX, 10SX, and 20 have it on the motherboard.

Crystal Semiconductor CS4231

Approximately the same as the T5900FC/CS4215 combination but without ISDN and an external codec; found in SPARCstation 4 (as an option), 5, and the current Ultra line.

Big Iron

Yes, the SPARCcenter 2000 is physically impressive, but remember that size doesn't matter. If you need the power and expandability of a 2000 and can afford it, you should be looking at a newer platform. I doubt many individuals are in such a position.

The story for the SPARCserver 1000 is somewhat different, but it still isn't a practical machine for most individuals. The 1000 is essentially a 2000 in a desktop enclosure with only one XDBus instead of two. Although it uses less power and is less expensive, the system's architecture is designed for moving large amounts of data: the higher latency suffered by most smaller operations is not good for most single-user workstations.

The only important difference of the E versions--the SPARCcenter 2000E and SPARCserver 1000E--is higher clock rates for the XDBus and SBus.

The 1000(E) and 2000(E) will run only Solaris 2.x; SunOS 4.x does not support sun4d.

The other big machines, such as the 4/600 and friends, are real beasts designed to fit the same card cages as the old 3/xxx machines and offer no performance advantages to the individual.

I dare say the Cray CS6400 is beyond the current scope of this document. It holds up to 64 60 MHz SuperSPARC (later UltraSPARC?) processors with 2 MB of cache each and 16 GB of RAM and requires 220 V three-phase power at 60 A. It runs a modified version of Solaris that can be partitioned into 16 virtual domains and requires an SSP (System Service Processor--usually a SPARCclassic) with a JTAG card. Now out of production and never very popular, it is the ancestor of Sun's Enterprise 10000. Lust fodder, indeed!

Disks

Some machines, such as the IPX, specify use of 1 x 33 and 4 x 33 SIMMs, which apparently have only one parity bit for all four bytes instead of a parity bit for each byte in the width of the chip. Regular fast page-mode 36-bit-wide SIMMs (i.e., Pea Sea) of the appropriate speed also work in such systems.

36-bit SIMMs should not, however, be mixed with 33-bit, as some memory controllers will discover the extra bits and use them for extended parity information and then fail when they encounter 33-bit SIMMs.

30-pin & 72-pin SIMMs

The form factor of the 30- and 72-pin SIMMs used is the industry standard.

SPARCstation 4 & 5

The SPARCstation 4 and SPARCstation 5 use fast page-mode 5 V 168-in JEDEC DIMMs. Thus they can use the DIMMs of the correct density from Apple PowerMac 7500s, 8500s, and 9500s if they have parity.

Processors

Sun's MBus, introduced with the SPARCsystem 600MP in 1991, is a circuit-switched processor/memory bus designed to support multiprocessing. In addition to the 6xx series, the SPARCstation 10 and 20 use the MBus to provide SMP capabilities. Each of those machines has two MBus slots; each slot holds one MBus module; each MBus module provides either one or two processors (see MBus module configurations).

Systems based on the MicroSPARC series of processors (including SPARCclassic, SPARCstation LX, SPARCstation 4, and SPARCstation 5) use the MBus only implicitly, as it is integrated into the processor along with the memory controller and SBus interface. Those machines are therefore incapable of SMP.

• Double-wide Each MBus module can hold one or two processors. A dual-processor module is twice as wide as a single-processor module and blocks the adjacent SBus slot in the SPARCstation 10 and SPARCstation 20. Such "double-wide" modules are necessary to achieve a four-processor configuration, as an MBus system can hold only two modules. (The Ross dual-processor modules are the exception--they hold two processors in the space of a single module.)
• SuperCache SuperCache is a 1 MB or 2 MB Level-2 cache for the processor. It is found only on Sun MBus modules with the TI SuperSPARC or SuperSPARC II processor. If a module has two processors, it has two SuperCaches: one for each processor. Some single-processor modules have no SuperCache. Modules that have 2 MB of SuperCache were designed for the SPARCserver 1000 and SPARCcenter 2000 but will work in the 10 and 20 as if they had only 1 MB of cache.
• Manufacturer Both Sun and Ross (neé Cypress) manufactured MBus modules. Sun's modules use the Texas Instruments SuperSPARC series of processors. Ross's modules use its own line of hyperSPARC processors. Some factory configurations of the SPARCstation 20 included Ross modules.
• Names Sun's modules have names like SMab, where a indicates (but does not enumerate) the speed, b indicates the presence or absence of cache, and c, if present, indicates the number of processors; or like SMxy-z, where a indicates the speed, y indicates the presence or absence of cache, and z, if present, indicates the size of the cache. (SM presumably stands for Sun Microelectronics.) (Sun Hardware Reference and www.sun.com apparently disagree about the dual-processor module naming; can someone explain?)

  Module Name	Speed (MHz)	Cache (MB)	Number of Processors	SuperSPARC Series
  SM20	33	0	1	I
  SM30	36	0	1	I
  SM40	40	0	1	I
  SM41	40	1	1	I
  SM50	50	0	1	I
  SM51	50	1	1	I
  SM512	50	1	2	I
  SM51-2	50	2	1	I
  SM61	60	1	1	I
  SM61-2	60	2	1	I
  SM71	75	1	1	II
  SM71-2	75	2	1	II
  SM81	85	1	1	II
  SM81-2	85	2	1	II

  One exception is the SM100, which has dual 40 MHz Ross processors and was intended for the 600 series.

  Ross's modules have names like HSxyz, where x, y, and z are only loose mnemonics for describing the module's characteristics. HS presumably stands for hyperSparc. If you can provide more complete information, please e-mail me.

  The model name of a SPARCstation 10 or 20 can be derived from the number and type of its modules. A Model 502, for example, has two SM50s; a Model 514 has two SM512s; a Model 712 has two SM71s. A Model HS11 has one HS11.

• Early modules The SM20, SM30, and most SM40s can be used only in single-processor configurations, purportedly because "early revisions of the SuperSPARC processor contained bugs that prevented MP configurations from working properly without the 1 MB external cache" (John DiMarco in the Sun Hardware Reference).
• SuperCache Modules that have cache cannot be mixed with modules that lack cache.
• MBus speed Modules must support the same MBus speed. For modules not equipped with SuperCache, the MBus runs at the module's speed; modules with cache must run higher than the MBus speed (which means running the 20's MBus below maximum speed in some configurations).

  Module Name	Module Speed (MHz)	MBus Speed (MHz)
  SM20	33	33
  SM30	36	36
  SM40	40	40
  SM41	40.3	40
  SM50	50	50
  SM51	50	40
  SM61	60	40 50
  SM71	75	40 50
  SM81	85	40 50

  Only the SPARCstation 20 supports the 50 MHz MBus speed. Modules that run the MBus at 50 MHz in the 20 will run it at 40 MHz in the 10. Thus, an SM50 in the 10 yields a 10/40. Only the SPARCstation 10 can use the SM20 (motherboard P/N 501-2274).

  The following combinations are supported and known to work:

  • 2 x later versions of SM40 (Model 402)
  • 2 x SM41 (Model 412)
  • 2 x SM51 (Model 512)
  • 2 x SM512 (Model 514)
  • 2 x SM61 (Model 612)
  • 2 x SM71 (Model 712)
  • 2 x SM81 (Model 812)

  The following combinations probably work but are unsupported:

  • 2 x SM50
  • SM41 & SM51 (known to work)
  • SM41 & SM61
  • SM51 & SM61
  • SM71 & SM81

  Note that SM41 and SM51 will run the MBus at 40 MHz in a SPARCstation 20, hindering the speed of a faster module like the SM61.

In summary, the only non-SuperCache modules that are capable of SMP are the later SM40s (and possibly the SM50s in the SPARCstation 20). Only combinations of SuperCache modules with processors in the same series are likely to work together.

Yet to come: XDBus, Weitek PowerUP, Cycle products.

June 8, 1999

Early version first announced on comp.sys.sun.hardware.

June 11, 1999

Added SPARCstation 5 and MBus info.

June 17, 1999

Added SPARCstation 10 and frame buffer info for IPC and IPX.

July 2, 1999

Updated speculation about compatibility of 36-bit SIMMS; added SPARCstation 20 info.

July 8, 1999

Added 160 MHz TurboSPARC to list of SPARCstation 5 processors.

July 21, 1999

Added information about SM50 in SPARCstation 10.

August 6, 1999

Confirmed comment about SM20 in SPARCstation 10. Added links to mention of Linux, NetBSD, and OpenBSD. Added more about SPARCstation 5 memory. Completed section on Sun 3s. Started to answer "Why Buy a Sun?" Made a slew of corrections and additions with comments from James Lockwood.

November 23, 1999

Added SPARCclassic, SPARCstation LX, and SPARCstation 4; added information about audio systems, CS6400, and AFX/S24.

December 21, 1999

Started work on keyboard section.

January 19, 2001

Removed references to my employer after objections from H.R.

March 29, 2001

Updated section on standard equipment and added sun4u to table of kernel architectures. Changed note on FAQ status.