| clock min        = 410 MHz

| package          = CBGA-359

'''X704''' (stylized as '''X⁷⁰⁴''') was a family of high-performance [[PowerPC]] [[microprocessor]]s announced by [[Exponential Technology]] in [[1996]]. At the time, these chips ran over three times the clock rate as [[Motorola]]'s/[[IBM]]'s or [[Intel]]'s (albeit not as fast in direct performance). Exponential experienced a few bumps in the road during the final stages delaying the final product and hindering their initial performance which did not meet their expected performance and power goals. Additionally, the X704 was caught in the crossfire between [[Apple]] and [[Macintosh clone]] manufacturers,  which ultimately sealed their fate (See [[#History|§ History]]).

In [[1994]] [[Apple]] and Exponential signed a joint development agreement and later that year they formed an agreement with [[Hitachi]] which agreed to manufacture their chip at their [[BiCMOS]] foundry. By [[1996]] with their chip just months away from [[engineering sample]], Apple's CEO, then [[wikipedia:Gil Amelio|Gil Amelio]] extended their agreement to gain exclusive rights to the chip for the first nine months of [[volume production]]. The deal included a $5 million prepayment - a payment Apple never delivered.  

First samples of the X704 came back running at only 410 MHz, 88% of the expected speed (or 75% of the top tier model). Exponential attributed the issue to a bug in their custom design tools. This pushed back the deliver date to March of [[1997]]. Even then, the chip would have been considerably faster than the fastest chips on the market at the time - Intel's {{intel|Pentium II|Klamath}} which ran as high as 233 MHz.

By February of [[1997]], the X704 was ready - hitachi delivered Exponential over 7,000 410-MHz chip. Apple was in a fairly bad shape at the time, with massive layoffs on the horizon; just a month later they acquired NEXT software for $430 million, bringing back Steve Jobs as an advisers and replacing key Apple upper management. Around the same time, Exponential displayed an X704-based machine to journalists at the LA [[wikipedia:Dreamworks|Dreamworks Studios]], running complex 3D animations and wowing the audiences. Following Exponential progress [[IBM]] announced a new chip: the {{ibm|Mach 5}}; the chip didn't actually arrive until 5 months later. While clocked at only 250 MHz, its considerably larger cache and wider datapath promised to match X704's performance. IBM chip was also to be manufactured on their new [[0.25 µm process]] (compared to X704's [[0.5 µm]]). Apple eventually went with IBM's chip but only for a short time as by 1998 they went over to PPC 750 series. In a meeting that took place on March 3 1997 Apple told Exponential that with the lay off of thousands employees they will no longer be able to design a system around the X704 chip. This decision had devastating consequences for Exponential which relied on Apple's deal which would've meant hundreds of millions of dollars in revenue.

On September 1 1997, Exponential sold their X704 patent portfolio, which amounted to over 50 patents, to S3 Inc for around $12M. Many of the technologies in these patents were used in Intel's {{intel|Pentium II}} processors. On December 1998 S3 Inc and [[Intel]] announced a 10-year patent cross-licensing agreement which gave Intel access to much of Exponential's original technology.

 

 

The X704 was an ambitious project for any company let alone a brand new start up. Many of the design tools were inadequate for the task and required Exponential to developed many new tools in-house including a custom [[standard cell|standard cell]] [[standard cell library| library]]. The final product was a {{ibm|PowerPC 60x}}-compatible, IEEE 1149.1-compliant, and IEEE 754-compliant [[microprocessor]] operating at over 400 MHz supporting a bus at up to 100 MHz.