Sun bares UltraSPARC; sees first silicon close

Electronic News, Sept 19, 1994 by Jim DeTar

BURLINGAME, CALIF. - Sun Microsystems, SPARC Technology Business (STB) unit will have first silicon on its new UltraSPARC-V9 processor as early as next month. As reported earlier (EN, June 27), Sun will today unveil its long-expected 64-bit UltraSPARC RISC processor family, which will offer devices ranging from 140MHz to 200MHz, and sources said within a few months a significant number of implementations of the new architecture will appear on the market.

Chet Silvestri, president of STB, said "UltraSPARC delivers the needs of enterprise network processing - flagship single-processor performance, exceptional multiprocessing support and the industry's most advanced on-chip multimedia capabilities. We've more than clearly raised the industry bar for RISC processing."

One of the multimedia capabilities of the new processor is what Sun calls a visual instruction set (VISual) - a feature that applies RISC principles to multimedia including streamlined instructions, data formatted in 8-bits, 16-bits or 32-bits for graphics and the ability to operate on up to eight pixels per cycle. The RISC processor is said by Sun to include on-chip multimedia support for desktop videoconferencing, real-time MPEG-2 decompression, video effects and texture-mapped triangle rendering applications.

UltraSPARC-V9 is composed of five main blocks. Execution is performed by nine functional units: "twin" arithmetic logic units (ALUs), a load/store unit, a branch unit, three floating point units (adder, multiply, and divide/square root) and both a graphics adder and multiplier. All are optimized for short latencies and high throughput, the company said.

Sun's new 3.8 million-transistor RISC processor will be fabricated by its partner Texas Instruments at that company's DMOS Fabrication Complex in Dallas. The devices will be manufactured on TI's EPIC 0.5-micron CMOS process. Additionally, UltraSPARC-V9 is optimized for 3.3-volt process and features 0.5-micron features, with an effective length of 0.45 micron, and four-layer metallization.

Sun's initial implementation will be at 167MHz, according to David Ditzel, Sun's director of the Sun SPARC Laboratory and chief scientist. In terms of performance benchmarks, the company estimates the multimember family's SPECint92 values to range from 200 to 400 with SPECfp92 values from 250 to 500. In addition, UltraSPARC-V9 offers multiprocessing capability that supports massively parallel processing (MPP) systems with up to 512 MPUs.

"When SPEC-95 comes out (the next expected benchmark suite), we will distance ourselves even further," Mr. Ditzel predicted. The planned second-generation UltraSPARC-2 is expected to offer up to 500 SPECfp92, he said.

UltraSPARC-V9 maintains binary compatibility with the more than 9,300 software and hardware products supporting the SPARC architecture. Its four-way superscalar design, dynamic branch prediction and single-cycle branch following, along with memory access structures, allow for up to four instructions per cycle even in the presence of conditional branches and cache misses, Sun said.

Looking to the future, Sun said the SPARC-V9 will support new programming styles such as: the microkernel operating system design approach, fast context switching and object-oriented software.

Linley Gwennap of the Microprocessor Report newsletter, commented that "Sun is three to six months behind schedule (with UltraSPARC) but they are coming in at a higher performance level than originally anticipated. So they're not doing too bad; they are doing a lot better than they have in the past."

Tony Massimini, senior processor analyst with market research firm In-Stat, said market execution on the UltraSPARC is critical not only from a perspective of maintaining credibility in terms its self-imposed roadmap, but also because Sun must stay competitive from a technology standpoint.

"With UltraSPARC they are still aiming at the high end of the workstation market. It's not something that's going to be challenging Pentium or mainstream processor. Obviously it is something Sun needs to do to keep a presence in that market. The high end workstation market is very small; in order to remain competitive they always need to continue advancing technology."