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DG/UX on UltraSPARC: Why?

We dig into Data General's decision to port
its well-regarded Unix to SPARC

By Barry D. Bowen

August  1995
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In May, Data General announced it would port its well-regarded 64-bit Unix operating system to UltraSPARC. Why? The answer is SPARC OEMs who are looking to move out of the traditional technical workstation market and into the more lucrative commercial market.

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In late May, at this year's SunWorld show held in San Francisco, Sun's SPARC Technology Business (STB) and Data General (DG) (Westboro, MA) announced that a 64-bit version of DG/UX would be ported to UltraSPARC. By mid-1996, everyone that wants to run DG's operating system on SPARC hardware can line up and buy a system -- but why?

The answer to that question is not readily obvious to many. Data General has a singular focus on providing high-end symmetric multiprocessing (SMP) servers to commercial environments. That's the same market SMCC and SunSoft aggressively target. Sun's kit-bag includes SPARCserver 1000 and SPARCcenter 2000 servers, and more recent versions of Solaris bundled with A+ Edition, the mainframe-class enhancements developed by Amdahl (Sunnyvale, CA). So why did STB seek out DG/UX, and why, at the same time DG was preparing to announce its future system architecture would be Intel-based, did it agree to port its OS to UltraSPARC?

The answer, at least for the next six months or so, is SPARC OEMs. STB is now sampling its 64-bit UltraSPARC chips at 143 MHz and 167 MHz. That provides a lot more horsepower for high-end servers, but to tap their full potential, a 64-bit operating system is essential.

SPARC OEMs have been looking to move out of the traditional technical workstation market and into the more lucrative commercial market, says Jeff Siegel, group manager for business development at STB. "That's DG/UX's strength. We really thought this through and tried to find a product that would help out customers. DG/UX has a strong customer base in commercial environments and that's where our customers want to expand," he says.

"In the short term, there are a number of SPARC OEMs trying to figure out how they will build an UltraSPARC system," says Frank Kinney, director of system software for Data General. "DG/UX will give them the opportunity, much sooner than they otherwise would, to have a true 64-bit operating system with excellent SMP scalability."


About DG/UX
According to Kinney, DG/UX was originally written with 64-bit addressing issues in mind. The kernel and file system, he said, were written for a 64-bit computer that DG designed a long time ago but never announced. So the amount of work necessary to modify the OS to support the 64-bit UltraSPARC chip will be less than that faced by other vendors.

"We feel we are a bit ahead of the game in having a 64-bit operating system. We've just never had a machine to run it on," says Kinney.

Clearly DG/UX is among the most prized assets of Data General, says Jay Bretzmann, director of world-wide system software research at IDC (Framingham, MA).

"DG started working on SMP scalability in about 1983, so they have a decade of tuning down, which is what it takes. It takes years to go through all the race conditions so that you optimize all the locking mechanisms," says Bretzmann.

"Many operating systems peak at 8 to 12 processors. Beyond that, users don't get much bang for the buck. DG has a 16-way platform with good scalability and they will introduce a 32-way system in the near future. DG/UX is high on the list of the company's protected assets," he says.

Data General also proudly points to an independent analysis of operating systems conducted by Illuminata (Hollis, NH), which took a functional look at several major Unix server OSes. The firm rated DG/UX superior to Solaris, AIX, OSF, and HP-UX, with particularly high marks in multiprocessing, matching the evolution of the OS to customer requirements, and the quality of the environment.

"Data General has been saying for some time," says Kinney, "that it would pursue a portability strategy for its system software. We will now deliver our OS on Motorola 88000, Intel, SPARC, and UltraSPARC platforms. This demonstrates to our customers that they can take a DG/UX application and easily move it to any DG/UX supported platform."

The 64-bit question
There is disagreement between STB -- whose charter is to promote the use of SPARC to the rest of the non-Sun universe -- and SunSoft and SMCC, on the impact DG/UX may have on the SPARC market.

SunSoft and SMCC were careful to politely acknowledge that STB's job is to promote SPARC, and that if DG/UX helps to do that, then that's a good thing. Reading between the lines of the firms' officially neutral stance on this issue, there seems little appreciation for why any one would want to run DG/UX on a SPARC-based server.

"I've read the reviews that give DG high marks for its commercial computing strategy, but the real obstacle for them is applications," says John Bard, product line manager of enterprise servers at SMCC. "Solaris and SPARC is the volume platform that will attract ISVs. It will be a rare application that will target DG/UX on SPARC that will not also be available on Solaris on SPARC."

"I am not aware of any application running on DG/UX that is not also running on Solaris," says David Spinhoff, director of product marketing for SunSoft. "We are the number one database platform, and all those apps are optimized for Solaris. DG/UX is certainly not number two or number three," he says.

STB and Data General spokespersons both note DG has some application strengths in providing turn-key applications to specific markets where Sun is less known, such as medical services and the insurance industry. The real draw, however, will be the impact of 64-bit addressing for large databases.

A 64-bit operating system breaks the 4 gigabyte address limitation of commercial database applications, says STB's Siegel. As commercial databases grow in size they will encounter that limitation more often and commercial users will be looking for a solution, he says.

"STB obviously sees the need for a 64-bit UltraSPARC operating system as more urgent than SunSoft," says Siegel, because STB went out and made this deal.

DG/UX will give SPARC OEMs targeting niche markets a way to differentiate themselves, Siegel says. To date, DG/UX is the only announced 64-bit operating system for the SPARC architecture.

SunSoft's position is that when the market is ready for a 64-bit operating system, they'll be ready to deliver. Only thinly veiled in this position is a hint that a 64-bit Solaris is not slated for release any time near the mid-1996 target date for the 64-bit DG/UX.

"We will definitely produce a 64-bit version of Solaris," says Spinhoff. "Our software products are optimized for UltraSPARC and will deliver the performance that customers demand. We will be there with a 64-bit OS when customers are ready for it. The information systems market has to swallow the transition to full 32-bit operating systems before they are ready for 64-bitness," he says.

Whether DG/UX will successfully leverage new SPARC OEMs, or get SPARC OEMs that have focused solely on desktop solutions to consider offering high-end SMP systems is up in the air. Both STB and Data General declined to say which firms have even expressed interest in the UltraSPARC DG/UX. Both also indicated they expected announcements would be made in the next few months.

An issue for any OEM will, of course, be application support. According to STB's Siegel, DG and STB will work jointly to encourage a select set of solution providers to support DG/UX on SPARC.

"Our goal is not to get thousands of applications ported to DG/UX on SPARC, but rather to get a handful of important commercial applications," says Siegel.

Playing the Intel card
Some analysts who track Data General express skepticism the DG/UX port to SPARC will produce big results. DG's announcement that its future hardware architecture will be based on 32-bit Intel chips implies Data General either isn't serious about UltraSPARC or will hold the 64-bit operating system in reserve for demanding users with mammoth datasets. Either way, ISVs face not one but two transitions to focus their energies.

"I don't know why integrators would port their applications for DG/UX on SPARC, when they are going to be busy supporting the new DG/UX for Intel platforms," says Rob Enderle, a senior analyst with San Jose, Calif.-based Dataquest.

"This deal makes me think that someone at STB had this on their list of things to do, and simply did it, rather than thinking very hard about why you would want to do this," he says.

DG's Kinney agrees that ISVs will consider an Intel port a higher priority than a port to a SPARC platform, but that should not preclude support for DG/UX on SPARC, he says. DG will ship an Intel platform in late 1995, so he believes the ISVs should be ready to tackle the SPARC version when it is available.

Kinney also asserts that since the complete operating system environment will be ported by DG, all ISVs will have to do is recompile.

"If you don't have assembly language, and you are not endian dependent, then it really is a recompile rather than a port. We are moving the entire system software stack to UltraSPARC. That includes all the libraries and compilers -- any place an application interfaces with a subsystem will have a DG/UX layer in place, so it should be a clean recompile," says Kinney.

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About the author
Barry D. Bowen ( is an industry analyst and writer with the Bowen Group Inc., based in Bellingham, WA.

Reach Barry at

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