NexGen, IBM lead MPU vendor feast

Electronic News, Oct 16, 1995

San Jose, Calif.--The semiconductor industry continues to surprise observers with its robustness as evidenced last week by the unveiling of a host of new processors here at the eighth annual Microprocessor Forum conference. Developments included the first look at NexGen's Nx686 processor (EN, Oct. 2), an Intel Pentium Pro competitor, as well as the first hard benchmarks from Intel on the Pentium Pro (previously code-named P6).

In addition, IBM debuted its Mfast (Mwave folded array signal transform processor) highly parallel, single-chip digital signal processor (DSP), an addition to the company's Mwave DSP family; and--targeting multimedia applications in the consumer PC arena--Philips disclosed further details of its TriMedia PCI-compatible multimedia processor.

NexGen is trying to get a jump on competitors by unveiling a sixth-generation x86 competitor--the company's second proprietary, high-end x86 design. Although Cyrix's forthcoming 6x86 (formerly the M1) Pentium/Pentium Pro competitor has been lauded for its feature set, it has also been criticized for having a relatively large die compared to the Intel and NexGen offerings.

Cyrix said at the forum that it is on track to begin shipping those processors within the next few weeks. And Advanced Micro Devices remains committed to rolling out its K5 Pentium competitor--currently shipping in limited quantities to Compaq--in the general market early next year.

As of today, however, NexGen is the only company shipping high-end x86 rival chips in volume. The NexGen Nx686 has approximately 6 million transistors and will debut at 180MHz internal operating frequency, manufactured using IBM Microelectronics' 0.35-micron, five-layer metal CMOS production process.

The Nx686 will build on the RISC86 Microarchitecture used in the Nx586 and extend this architecture by decoding multiple x86 instructions per clock cycle, which are fed into seven execution units. These consist of two integer execution units, one floating point, one multimedia, one memory load, one memory store and one branch execution unit.

In an interview, NexGen COO Vinod Dham said the company is planning to have the Nx686 in the market in the same time frame that Intel's Pentium Pro will be shipping.

Mr. Dham said, "0.35-micron should get us to 200MHz and beyond. We expect the chip will be available in the first half of next year." The company will move to a 0.25-micron process shortly after that. NexGen also said the device is expected to be offered at a comparable price to the Pentium Pro, or possibly below it depending on forthcoming final benchmark numbers for the Nx686 which will determine the relative price/performance of the chips.

NexGen has said for some time that it intends to broaden its manufacturing base as it ramps production, and Mr. Dham hinted that the company is on the verge of announcing another manufacturing partner.

He also confirmed reports that the company has signed an agreement with Samsung for chipsets, and that NexGen is also in discussion with Taiwan-based United Microelectronics Corp (UMC) to deliver chipsets. "Yes, we have an agreement with Samsung and we are in discussion with UMC and others, but nothing has fully materialized yet." Samsung is expected to begin delivery of the chipsets by the end of this year.

NexGen also recently renegotiated its manufacturing agreement with IBM in order to purchase substantially more 586 units at significantly lower prices in order to match Intel's aggressive pricing. "IBM has given us an idea of capacity for next year and the price is substantially lower."

Mr. Dham added that the next few quarters will be a crucial period for the company as it attempts to reach critical mass in terms of unit shipments and revenue generation.

Intel, meanwhile, revealed for the first time some hard benchmark numbers for the 150MHz version of the Pentium Pro. Robert Colwell, chief architect for the device, said the 150MHz Pentium Pro, manufactured on Intel's 0.6-micron process, will be available shortly. "It will be announced in a few weeks with 256K of L2 cache," Mr. Colwell said.

The 150MHz Pentium Pro has now been benchmarked at a SPECint92 number of 276.3, and a SPECfp92 rating of 220. On the recently-released SPECint95 and SPECfp95 benchmarks, the device reaches 6.08 and 5.41 respectively.

One question Mr. Colwell addressed is exactly how many stages of pipelining does the Pentium Pro have. The device is specified to have eight in-order front end stages, three out-of-order core stages and three in-order retirement stages. But the number of stages in an implementation can vary, he noted.

"How many pipestages does P6 have?" he asked rhetorically, answering: "A lot; exactly how many depends on many things." He gave a rule-of-thumb that it will have 15-20 cycles for integer operations and 30 for floating point operations.

Also at the conference, IBM provided a first look under the hood of its Mfast DSP. Gerald G. Pechanek, architect of the of the device, said the new DSP will extend the architecture of the existing 3000 Series which features DSVD telegaming and two-line telephony capabilities.