Sun maps out 64-bit UltraSPARC

Electronic News, June 27, 1994 by Jim DeTar

MOUNTAIN VIEW, CALIF.--Sun Microsystems is counting on its new 64-bit UltraSPARC architecture to propel the company back into the microprocessor performance race. The first implementation of UltraSPARC will be the V9, which will be fully binary compatible with SPARC-V8 and is scheduled to tape out in August and achieve first silicon this fall (EN, Antenna, June 20). Even so, it will be several years before 64-bit computers become the norm.

David Ditzel, chief scientist and director of SPARC Labs for Sun Microsystems SPARC Technology Business, said in an interview with Electronic Newslast week that the SPARC-V9 took three years to design. "The V9 will put SPARC back in the performance lead. We'll give our users a real big jump in performance to get started--a factor of five or so."

The SPARC-V9 will have approximately 4 million transistors, will offer internal clock speeds in the 150MHz to 200MHz range and will have a SPECint integer performance rating of 250 to 300 and SPECfp floating point rating of 300 to 500, he said.

The SPARC-V9 processor will do four instructions per cycle and will be fabricated on 0.5-micron CMOS technology designed by Texas Instruments. "TI has a billion-dollar fab site that will bring up 8-inch wafers. That will be our main production line for UltraSPARC-1. They are already on a learning curve for UltraSPARC," according to Mr. Ditzel. UltraSPARC-1 will be quickly followed by UltraSPARC-2 which is slated to achieve speeds of 250MHz to 300MHz. Finally, around the 1997 time-frame, the Sun roadmap calls for the introduction of UltraSPARC-3, which will run at about 500MHz.

"We are already under development with UltraSPARC-3," Mr. Ditzel noted. "UltraSPARC-3 will be straight CMOS, and the process will probably be 0.35-micron." UltraSPARC-3 is expected to attain a SPECint rating of beyond 1,000, and a SPECfp rating above 1,500. The projected 1997 introduction date for UltraSPARC-3 is slightly ahead of the timetable Intel and Hewlett-Packard have set for early sampling of the 64-bit x86/Precision Architecture-RISC compatible chips they recently said they will co-develop (EN, June 13).

Sun's future direction for SPARC calls for three families of processors: future versions of the existing MicroSPARC for lowest cost desktops; the SuperSPARC line, which addresses mainline desktop systems and offers upgradable multiprocessor support; and the new UltraSPARC, including V9, which is focused on multiprocessor performance for workstations.

In the immediate future, the shift to a 64-bit architecture in the imminent SPARC-V9 is a move designed to extend the life of the SPARC family to the next century. Sun must push forward with its next generation processor in the face of challenges from the PowerPC developed by IBM, Motorola and Apple Computer or Digital Equipment Corp.'s Alpha RISC chips, as well as the continuing steep ramp of the market-leading Intel Pentium CISC processor--which is now targeted at the workstation market.

Although Sun remains the number one workstation vendor in unit sales--in part because of its software advantage with approximately 8,000 SPARC software programs now available--SPARC system sales are flat, Sun is losing market share in the workstation market. Its share is down 1 percent according to Dataquest, while workstation competitors such as HP, which is up 4 percent, and Silicon Graphics, up 2 percent, eat up market share with new products.

That is one reason Sun is touting the performance features of the V9. The company's implementation of 64-bit virtual addressing, for example, will enable a raft of related features such as: All integer registers are extended from 32 to 64 bits, a new condition-code register gets set from the 64-bit values, and several new instructions will be able to manipulate 64-bit values. Existing V8 program instructions will still operate on registers directly but will only utilize the low 32 bits of the register. Therefore, all V8 instructions and programs are expected to get exactly the same results on V9 MPUs as they do on V8s.

Having had a difficult time with other product transitions, such as the early release period of Sun's Solaris 32-bit operating environment, the company is now committed to full binary compatibility on SPARC-V9.

"We goofed. I have apologized for it in the past. The good news is that we've gone and fixed it and worked hard on the compatibility issues and all the rest of it," Sun president and CEO Scott McNealy recently said of the flubbed transition to Solaris 2.0. "We've fixed the binary compatibility package and the linking issues and really worked hard to put that compatibility back into Solaris. I've been there, and I've done that with respect to transitions. And read my lips, 'No more transitions.'"

Although there will be early adopters, the fact is, Mr. McNealy said, it will be awhile before systems built on the SPARC-V9 platform and other 64-bit processors become available. "Once you get the chip, then you build the software, then you build the development tools, then you build the application environment. I would imagine it will be a three to five-year migration before 64-bit becomes a volume standard kind of computing platform," he said, adding "There will be some early adopters, some people who have very large address space needs and that sort of thing."