The Quest for More Processing Power, Part One: "Is the single core CPU doomed?"
by Johan De Gelas on February 8, 2005 4:00 PM EST- Posted in
- CPUs
Conclusion
Prescott was built to adapt to the typical problems that made it hard to run x86 programs quickly: branches, dependencies, lots of memory and ADD operations. However, in order to do so, complex logic was used, which increased leakage power quickly. The wire delay problem and dependency problem were only solved by sacrificing a lot of energy. The combination of LVS double-pumped ALUs, tons of new features and 64 bit together created an avalanche of leaking logic. The result is an innovative architecture crushed into a thermal wall.
But the Prescott failure, the exploding leakage power and wire delay don't mean automatically that the single core CPUs have no future. Power leakage can be contained by introducing high-K materials and SOI. Wire delay has been solved by using repeaters - at the cost of some extra power - and Cu interconnects. Dual core is not a magical solution that is going to solve all the problems that Prescott and other modern CPU face.
The Prescott failure only tells us that right now, the ultra deep pipelined CPU is not the best solution. Intel went too quickly, too deep, and although many ingenious tricks were implemented to make the Prescott a real powerhouse, all those tricks together backfired with high leakage and dynamic power loss.
In the next article, we investigate what dual core technology can really bring us, besides a lot of hype, "paradigm shift" slogans everywhere and "much smoother system" claims.
References
[1] An In-Depth Look at Computer Performance Growth
CHALMERS UNIVERSITY OF TECHNOLOGY, Department of Computer Engineering, Göteborg 2004
http://www.ce.chalmers.se/~warg/papers/performancegrowth_tr-2004-9.pdf
[2] Intel Whitefield uncovered, The Register
http://www.theregister.co.uk/2004/05/01/intel_whitefield_uncovered/
[3] Implementing Power Management IP forDynamic and Static Power Reduction in Configurable Microprocessors using the Galaxy Design Platform at 130nm
Dan Hillman, Virtual Silicon
John Wei, Tensilica
http://www.tensilica.com/hillman_slides.pdf
[4] Leakage Power Modelling and Leakage Power Modelling and Minimization
Massoud Pedram
University of Southern California , Dept. of EE-Systems
http://atrak.usc.edu/~massoud/Papers/pedram-tutorial-iccad04.pdf
[5] Gigascale Integration-Challenges and Opportunities
By Shekhar Borkar
Intel Fellow, Director, Circuit Research
http://www.intel.com/research/mrl/research/circuit.htm
http://www.intel.com/cd/ids/developer/asmo-na/eng/strategy/182440.htm?page=1
[6] SUN Niagra Demo
http://www.sun.com/aboutsun/media/presskits/networkcomputing05q1/
[7] LVS Technology for the Intel® Pentium® 4 Processor on 90nm Technology
http://www.intel.com/technology/itj/2004/volume08issue01/art04_lvs_technology/p01_abstract.htm
Other Sources:
- Intel Silicon Innovation To Shape Direction Of The Digital World
Multi-Core Processors, FALL IDF 2004
http://www.intel.com/pressroom/archive/releases/20040907corp.htm - Pentium 4 processor at 4.7 GHz, FALL IDF 2002
http://www.intel.com/pressroom/archive/releases/20020909corp.htm - Intel Developer Forum, Spring 2002
Louis Burns Keynote, Netburst architecture scales up to 10 GHz.
http://www.intel.com/pressroom/archive/speeches/burns20020227.htm - The Free Lunch Is Over: A Fundamental Turn Toward Concurrency in Software
By Herb Sutter
http://www.gotw.ca/publications/concurrency-ddj.htm - Illinois researchers create world's fastest transistor ... again
http://www.news.uiuc.edu/scitips/03/1106feng.html
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AnnoyedGrunt - Tuesday, February 8, 2005 - link
It's possible that 22 was referring solely to the grammar of the sentence, which could potentially make more sense if it was rewritten as, "while other applications will REQUIRE exponential investments in develpment....."Very good article overall, but some portions could be polished a bit perhaps to make it easier for people only slightly familiar with processor details (people like myself) to understand.
Really looking forward to part 2!
-D'oh!
JarredWalton - Tuesday, February 8, 2005 - link
23 - Not at all. Have you ever tried writing multi-threaded code? If it take 12 months to write and debug a single-threaded program that handles a task, and you try to do the same thing in multi-threaded code, I would expect 24 to 36 months to get everything done properly.Let's not even get into the discussion of the fact that not all code really *can* benefit from multi-threadedness. I had a similar conversation with several others in the Dual Core AMD Roadmap article. You can read the comments there for additional insight, I hope:
http://www.anandtech.com/talkarticle.aspx?i=2303
cosmotic - Tuesday, February 8, 2005 - link
"while the other applications will see exponential investments in development time to achieve the same performance increase." Thats a really stupid statement.cosmotic - Tuesday, February 8, 2005 - link
That first image really sucks. You should at least make it look decent. It looks like crap now.IceWindius - Tuesday, February 8, 2005 - link
Math hurts, and thus my head hurts.......Either way, Intel finally admits they fucked up and AMD spanked them for it. Justice is served.
faboloso112 - Tuesday, February 8, 2005 - link
only about halfway through the article but this is a damn good article.not a fanboi of any sort but i certainly do hate intel's pr team.
i think the reason amd has done well for itself is because it doesn't pride itself nor relies of fake product specs and their exaggerated capabilities and scalability...unlike intel...and ill admit...i got cought up in the hype too with the whole 10ghz thing at the time because based on moore's law and how things had been going w/ the clock speed jumps...i thought one day it would be possible...but look at where the prescott stands now...and look at how instead of blabbing about 10ghz..they talk of multi-core cpu.
i think ill stop talking now and return to the article...
erikvanvelzen - Tuesday, February 8, 2005 - link
i eat these sort of articles about cpu's, memory and the like which have references to hardware which i actually use.If you like this, check out these articles by John 'Hannibal' Stokes @ arstechnica.com:
http://arstechnica.com/cpu/index.html
http://arstechnica.com/articles/paedia/cpu.ars
jbond04 - Tuesday, February 8, 2005 - link
AWESOME article, Johan. Good to see someone do some real research regarding the Prescott processor. Keep up the good work!Oxonium - Tuesday, February 8, 2005 - link
Johan used to write very good articles for Ace's Hardware. I'm glad to see him writing those same high-quality articles for Anandtech. Keep up the good work!BlackMountainCow - Tuesday, February 8, 2005 - link
Wow, very interesting read. Finally some stuff based on real facts and not some "Prescott just sux" stuff. Two thumbs up!