THE SUPER-BRAINS: a look at PC processors
BY SA MOHD SAARI
ISE 2
INTRODUCTION
It’s been a long time since the first of the microprocessor made its first appearance. It was 1971, with 4004 by Intel Corp. Amazingly, it was not for the PC, which came 10 years later with IBM PC. From then, came members of the 80X86 family (8086, 8088, 286, 386, 486, Pentium…) with Pentium2 the youngest member, set to rule the PC market. There are many other microprocessors no doubt: Harris 1802A, Hitachi 64180, Arizona 16C55, Amd-K5, Cyrix-M1 and countless others of which many are not known by the general consumer and does not enter the PC industry.
So, who are the main players of the game you might ask? …The are several big ones: Intel the Giant of the market, IBM, Motorola, Cyrix, Amd and Digital Corp among others. The market is hungry for nothing but the ‘best’, ‘fastest’ and ‘powerful’ PCs. It is only natural that the development of the microprocessors goes on an equal if not leading pace. This article review some of the exciting developments and endeavours by major microprocessor manufacturers towards the end of the century…
THE PLAYERS:
486
At the end of 1995, Cyrix happily pulled out of the 486 market citing lack of demands and piling stock as the main reasons. Nothing much can be said about it now…Maybe there is still a reasonable market share for it, as AMD claimed that very same year?
Classic Pentium
Introduced in 1993, the Pentium is already a household PC name together with the IntelŪ inside logo synonymous with most of the PCs. Currently, it still holds the mainstream of the consumer market, with 75Mhz, 90MHz, 100MHz, 120MHz, 133MHz, 150MHz and 200MHz processors. Its main features include Superscalar Architecture, Dynamic Branch Prediction, Pipelined Floating-Point Unit, Improved Instruction Execution Time, Separate 8K Code and 8K Data caches, Writeback MESI Protocol in the Data Cache, 64-Bit Data Bus, Bus Cycle Pipelining, Dual Processing Support and SL Power Management Features. Pentiums are produced by an advanced semiconductor technology with 0.35 micron BiCMOS (Bipolar CMOS) process and multiple layered metal (to decrease component distance). Generally (for 120,133,150,166 & 200MHz), the PentiumŪ processors contain 3.3 million transistors running on 3.3 volts. Intel was also able to place components (i.e. math coprocessors, caches & multiprocessor interrupt controller) on-board the chip, decreasing access time and increasing performance.
In June 1996, Intel introduced the 200 MHz PentiumŪ processor. But today, the fate of the Classic Pentiums may as well follow its predecessors-‘squeezed out’. With Pentium Pros and MMX-enabled Pentiums, it is highly unlikely that Pentium will remain the main choice of today. Applications (Video conferencing, Imaging, games and others) may also demand MMX technology.
"Between them, these two choices offer such intriguing price/performance benefits, it's hard to see why you'd stick with a plain old Pentium", Bill Howard, zdnews
Intel has already admitted it won’t be making Pentiums above the 200MHz-clock speed. Pentium 2 is set to continue the 80X86 increasing speed and power staring at 233MHz.
Pentium Pro
The Pentium Pro (dubbed P6 in its development stage) has a totally different architecture from the classic Pentiums. The fact that it was called with a ‘Pentium’ name was probably another of Intel’s marketing strategy. Introduced in autumn 1995, Pentium Pros are based on RISC (Reduced Instruction Set Computing) architectures with 256 or 512Kb Level1 cache and dynamic execution (data flow analysis, multiple branch prediction & speculative execution). Pentium Pros are superior to the classic Pentiums when dealing 32-bit applications but losses out on 16-bit applications. Therefore, Intel has proposed the Windows NT™ as it Operating Systems pair. Production-wise, the chip requires an expensive on-dye cache, which explains why it is too expensive for the normal consumer. It started out in the high-end server and business market hoping to enter the mainstream of the consumer market with increasing production and dropping prices. But this never came through. Maybe, the tough price-cuts on the Pentium Pro has had Intel changed its strategy redesigned the chip to produce the Pentium II.
Pentium II
Yes, it’s finally here. The Pentium II, as Intel claims is the new ‘Highest Performance Processor ’ member of the Intel family. It runs at 233, 266 and 300 MHz. Intel has also made a prototype for a 400MHz. The new chip on the block introduces a different outlook from its predecessors, apart from the Dynamic Execution and Dual Independent Bus Architecture first adopted in Pentium Pro chips. It has higher core speeds and support MMX functions.
The chips however may loose out to the Pentium Pros on high-end applications performance. It also has new processor –to-cache bus (@ backside bus) with half the speed of the processor. The new outlook comes in the form of S.E.C. (Single Edge Contact) Cartridges which fits into also a new SLOT1 module instead of the previous PGA socket (socket 7). The SEC hosts the core chip and the L2 cache.
"These sub-components are surface mounted directly to a substrate inside the cartridge to enable high-frequency operation. The S.E.C. cartridge technology allows the use of widely available, high-performance industry BSRAMs for the dedicated L2 cache, enabling high-performance processing at mainstream price points", Intel
Besides, it is less costly and more easily produced than the Pentium Pros.
MMX technology
The 1996 Microprocessor Conference in San Jose, California saw the focus to come would be towards specialised microprocessors optimised for multimedia. Just some time ago, Intel introduced MMX, which received tremendous response from Intel’s customers. There has been strong support from software and operating systems developers to generate MMX designed software. Had it not been for some creative teams at work at Intel MMX would never be. The MMX technology introduced 57 new instructions to speed up multimedia (video, audio & graphical data). It was based on the clever analysis on where multimedia applications spend most of its time and optimising hardware to deal with it. It also incorporates a process called Single Instruction Multiple Data (SIMD) which enables one instruction to perform the same function on multiple pieces of data MMX utilises a 64bit register (from the floating point architectures already build in Intel architectures) apart from the increased 32-bit on-chip cache. Intel has already incorporated MMX in its Pentiums.
MMX looks like it is likely to stay…
Amd’s K6
The K6 has RISC-base with extra hardware to translate X86 instructions. It implements a 64-bit primary cache, with separate data and instruction cache. K6 also supports MMX operations with an added set of registers to reduce the switchover time (between different kinds of operations). This it claims will be faster than Intel’s switchover time of 47 clock cycles.
Cyrix’s M2
Cyrix made quite a progress last year with many of its 6X86 processors marginally faster the Pentiums with the same clock speed. The new M2 processor, to be released in June, should put up a fight with Intel’s newly introduced Pentiums. The chip based upon CISC(Complex Instruction Set Computing) has a few distinctive features. Firstly, it makes use of a 64bit primary unified cache, which shares the cache for data & instruction via some dynamic placement. It also has a 512 branch-target-cache to predict the most likely instruction sequence flow. M2 also supports all 57 MMX features with reduced-switch times (relative to Intel’s registers). Cyrix also promises some extra graphics performance with M2. Unlike Pentium 2, M2 supports the current Socket 7 zif socket. And it also contains 75% less transistors than AMD’s K6.
PowerPC
The PowerPC is a product from the joint effort of Apple, IBM and Motorola (the AIM alliance) based on the RISC architecture. It claims to host an open standard, not tied to any operating system, application, or hardware configuration that allows the innovation of new systems. Among the others are the PowerPC 604e and PowerPC 603e. Not much of the PowerPC will be mentioned here, just enough to note their presence in the striving CISC and RISC camps of the microprocessor industry, which will greatly influence the processors to come.
THE CHIP WARS
RISC & CISC Tribes
In view of the great race of the RISC and CISC camps in the PC microprocessor industry, one important aspect to note is software compatibility and availability. The fact remains that there are just too much of CISC software around, more than the platform uses or needs. To acquire a significant niche of the market, RISC developers need to tackle this issue. One project, dubbed PowerPC 615 by IBM. There are reports of it being a hybrid chip to handle both PowerPC & X86 codes. Other techniques include software emulation, double processor (‘the two-headed beast’) with X86 and PowerPC chip in a single system, binary translating the X86 codes into PowerPCs and software emulation with hardware assistance.
THE LEGAL BATTLES
In my previous article (‘PC-the People Factor’) I have noted the intense legal battles in the PC industry. The microprocessor industry poses the similar scenario with constant suit and counter-suit on patent infringements allegations. Current legal battles may revolve around the Pentium Pro, Pentium II and MMX technologies, among others.
Is that Intel inside...or more like (…) down there? He who patents wins…probably is the saying in the chip industry.
THE GOLDEN TRIANGLE : Intel/AMD/Cyrix
Intel seems to be in a controlling position of the chip industry. Since 1992, its sales increased to $21 billion with net profits $5 billion. Its ‘Intel Inside’ has penetrated into our lives just like ‘McDonald’s’ or ‘Coca-Cola’ making it hard on the competitors. It also host a list of major customers also well known in the customer market for its quality & reliability. How do Everex, CyberMax, Evesham Micros and Elonex against the host of Intel’s major customers? Not much?
Intel has 80% microprocessor market share. Its achievements can be attributed to its cunning and timely tactics in the ever-competitive market. In the 80’s and 90’s, it engaged on a legal and cross-licensing strategy. Gaining in time to develop and market as competitors are diverted in courts and re-rooted monetary resources which could’ve been better used in developments. In the 90’s, Intel worked on its development teams, making the lead in technology, forcing rivals to follow its suit, trailing, though sometimes surpassing it. Even, the Pentium II practically is to Intel’s advantage. Intel’s decision to revert to
SER cartridges fitted onto the SLOT1 module just signals to the market that the current Socket 7 is ‘old-fashion’. Intel holds the SLOT1 patent. Even if license it out, competitors will be need time to catch up.
The large grip Intel has on the market, will force AMD, Cyrix and others of the like to revert to ‘guerrilla tactics’ in the battle to stay in the market. The tactics include pinpointing the competitor’s weak spots, setting low targets, Create a no-win position for the opponent, pooling resources, ‘vapourware’ (always hint of a better product in-hand), undercut prices, surprise, accuse, hijack the opponent in court among others. But will this tactics work against Intel?
THE NEW CHIPS TO COME…
Intel has promised to develop the X86 architecture 10 times in current state in a mere 3 years. It focuses on 5 PC architecture: processor, memory, graphics bus, graphics accelerator and I/O. Will we then see a 2GHz PC by the year 2000? Or will it be from the projects already in our Research labs (quantum computing, molecular processors & optical processors)? Only time will tell? But it is most likely that Intel will have say in it…
SOURCES:
State of the Art: ‘Chip Fashion’, by Tom R.Halfhill & John Montgomery, BYTE Nov 1995.
State Of the Art: ‘CPU Scorecards’, by Dick Pountain & Tom R.Halfhill, BYTE Nov 1995.
State Of the Art: ‘Why the 615 matters’, by Linley Gwennnap, BYTE Nov 1995
Intel Changes: ‘Chip to chip’, Andrew Ward, Computer Shopper June 1996, Page 567
Hands On: ‘Lessons from a Pro’, Marcus Austin & Mike Bracken, PC Direct 1995, Page 378
‘Pentium- better the second time around’, Simon Williams, PC Plus June 1997, Page 37
‘Intel’s ten-speed promise’, Simon Williams, PC Plus June 1997, Page 38
Special Investigation: ‘Chip Wars: Can the Rebels Win’, by Jason Thomas, PC Plus June 1997, Page 44
‘And M2 makes three’, by Simon Williams, PC Plus June 1997, Page 55
Microprocessor 25th Anniversary: ‘Hi Ho Silver’, by Mike Bedford, Computer Shopper 1997, Page 651
Cover Story: ‘What’s Next’, by Tom Thompson, BYTE April 1996, Page 45
Bye Bye Pentium?’ by Bill Howard, http://headlines.yahoo.com/zdnews/stories/852058222.html
Intel Introduces 200MHz PentiumŪ Processor, http://www.intel.com/pressroom/archive/releases/pp200.htm
Manufacturing Process Technology, http://www.intel.com/procs/pentium/pp120/process.htm
Intel Sees Strong Pentium II Sale, by Joseph Ng, http://www.yahoo.com/headlines/970513/tech/stories/intel_1.html
Cyrix Files Patent Suit Vs Intel http://www.yahoo.com/headlines/970514/tech/stories/cyrix_1.html
Economist : Intel http://www.economist.com/issue/10-05-97/wb8764.html