The content of this blog is my personal opinion only. Although I am an employee - currently of Nvidia, in the past of other companies such as Iagination Technologies, MIPS, Intellectual Ventures, Intel, AMD, Motorola, and Gould - I reveal this only so that the reader may account for any possible bias I may have towards my employer's products. The statements I make here in no way represent my employer's position, nor am I authorized to speak on behalf of my employer. In fact, this posting may not even represent my personal opinion, since occasionally I play devil's advocate.

See http://docs.google.com/View?id=dcxddbtr_23cg5thdfj for photo credits.

Tuesday, December 22, 2009


Will markets like IPXI allow inventors to be more independent of big companies? Will they promote innovation?

in reference to: IPXI (view on Google Sidewiki)


Will markets like IPXI allow inventors to be more or less independent of big companies?

in reference to: IPXI (view on Google Sidewiki)

Download My SideWiki

I would like the ability to save all of my sidewiki entries, on all pages anywhere.

I would like the ability to save sidewiki entries from others that I have tagged.

I would like my sidewiki to be integrated like a bookmark server like del.icio.us

in reference to: Google Sidewiki (view on Google Sidewiki)

Monday, December 07, 2009

People are using personal computers at work

I have long maintained "the craftsman owns his tools", and that, since the computer is my main tool, I should therefore own the computer I work on.   Especially since IT departments so often provide lousy computers to employees.

This Inquirer article says "People are using personal computers at work". Around 1 in 10, and growing.  Cost savings of 9 to 40%. IT departments resisting.  A growing trend, perhaps instigated by the recession, but, I hope, becoming more prevalent.

For years I used my own personal computers.

At Intel, one of the earliest personally owned computers I used was my Compaq Concerto pen computer circa 1994-2000 - which I bought because I wanted to prove that speech recognition was better than handwriting recognition, and which I fell in love with.  A succession of tablet PCs.

At AMD, when I started writing the K10 proposal I went out in the morning to buy a Wacom tablet at Frye's.  Drawing on this was so frustrating that at lunch I went out and bought a Toshiba Portege 3505. I wanted to connect it to external video, but the cables stuck out awkwardly into my lab, and there was no software screen rotation - so I took the external monitor and flipped it over, using the styrofoam packing cases to support it upside down.

Unfortunately, when I returned to Intel in 2004 IT had clamped down.  No personal computers allowed to be connected to the Intel network.  Company provided laptops only.  I wasn't allowed to use a tablet PC.  No matter that drawing was part of my job.  Tablet PCs are only for managers. Ditto Blackberries or any other device that allowed you to look at your calendar without having to wait 15-30 minutes to reboot.  No matter that 10 years earlier we all carried pagers that werepinged for meetings - once IT took over, no personal equipment, and technology regressed.   Frustration at this is one of the reasons I left Intel - although I will give Doug Carmean of Larrabee credit, he was much more willing to push IT and get his engineers the equipment they needed.  For this reason, if no other, I hope that Doug and Larrabee overcome the adversity announced today.

My current employer's IT department tries to clamp down.  I use a company provided notebook PC because I must keep my personal work and my company work strictly separated - to protect MY rights as an inventor in my spare time.  But, I have 5 LCD displays at work, 3 which, with their 3 USB display adapters.  Plus keyboards.   IT insisted on buying me a trackball, and I have been told that IV will purchase displays and adapters and keyboards such as I want.  But, purchasing my own allows me to experiment - to try to find the combination of equipment that makes me most productive.

After all, my productivity is my business.  It influences my success at work, and how much I enjoy my work   IT is often motivated by cost reduction as often as they are motivated by productivity.

This is not specific to the IT departments of my past or current employer.  It seems to be true of all IT departments.  I have seen exceptions only (a) during the P6 project, when we essentially had project specific, non-corporate, computing support, and (b) at University.  Perhaps also (c) at the Little Software House on the Prairie.

I admit an ulterior motive: I hope not to be an employee forever. I want to be independent.  Perhaps consulting for my current employer.  Perhaps something else.

But, whatever: I don't want to have to deal with productivity limiting IT departments.

The PC Revolution happened in large part because individuals could purchase PCs outside the control of corporate IT departments.  But the corporate IT departments caught up, and regained control.

Speech vs pen vs keyboard vs ALPs pad

Last Friday I posted to Facebook about how happy I was with my end of week Seattle to Portland commute.  I was only person in the van, so I plugged in my headset mike and started dictating via Vista's built-in speech recognition. Sweet!  Most productive 4 hour van ride I have yet had.

This Monday morning's commute there are 2 other passengers. Sleeping.  I don't want to wake them, so I have been reading USEnet news and Gmail using my pen. Handwriting replies, but mainly point and click.  Useable, but doesn't feel as productive.

Typing this on keyboard.  Not as nice as speech.  Errors caused by bouncing of van.  Mainly due to ALP pad: van bounces, hand brushes pad, typing goes astray.  I think that I will have to disable ALP pad while in van, get another pointing device.  Wish I had an IBM style pointing stick. Q: what other non-ALP pointing devices are there, that can be used in a bouncing van?

Bottom line:  for a bouncing van (also, bouncing small commuter planes):

Speech wins, if not annoying others

Pen/handwriting okay

Keyboard maybe

ALPs pad loses

Wednesday, December 02, 2009

Thought during in my morning bicycle ride: BO and Date of Urbanization and Transportation

Thought during in my morning bicycle ride:

It is well known that Americans seem to be more sensitive to body odor than many other countries. As I was having my shower after my bicycle ride, I wondered if this might be due to the fact that European countries started commuting into big cities earlier than in the United States. The United States was quite an agrarian nation even up until the first world war. When the United States urbanized, public transportation on buses and streetcars and trains was quite common, and eventually the United States became the automobile civilization. Whereas Europe urbanized earlier, so people were commuting by walking or bicycling etc. which meant that the European worker class, and even the European office bureaucrat class, got to work a little bit smellier, unless they had a shower. Which wasn't common until the end of the 20th century. I think about Andy Grove saying "there will never be showers at Intel", and I wonder if this was perhaps a Czech attitude.

The United States has many more humid areas in the American South than most European countries do.  This might also explain. Especially since being sweaty and hence smelly was indicative of class.

Tuesday, December 01, 2009

Links to MLP, Coherent Threading, Multistar

Urgh. Let me just add some links to the blog, from my Google docs "website" root:

Other Stuff

* MLP Yes! ILP No!
o presentation I gave at ASPLOS 98 WACI session
o preserved for more than 10 years by the session organizer at http://www.cs.berkeley.edu/~kubitron/asplos98/final.html,
+ specifically http://www.cs.berkeley.edu/~kubitron/asplos98/slides/andrew_glew.pdf
o a copy kept on Google docs: http://docs.google.com/fileview?id=F.cb345d6b-c4ac-40c6-9e71-bf5d4d18af55
+ it is unclear if Google docs allows anyone to read this -i.e. it is unclear if one can "publish" to the world an uploaded presentation

* Multistar:
o The Story Behind Multistar: http://docs.google.com/View?id=dcxddbtr_40czbtrtf2
o Multistar PDF (2004): http://docs.google.com/fileview?id=0B5qTWL2s3LcQZDIyZDVmN2EtYjY4MC00YjU2LWE4ZGMtYzk2MmU4M2U2NDQ5&hl=en

* Berkeley ParLab talk on Coherent Threading: (2009)
o Coherent Threading
Coherent Vector Lane Threading (SIMT, DIMT, NIMT)
Microarchitectures Intermediate Between SISD and MIMD, Scalar and SIMD parallel vector
o http://docs.google.com/fileview?id=0B5qTWL2s3LcQNGE3NWI4NzQtNTBhNS00YjgyLTljZGMtNTA0YjJmMGIzNDEw&hl=en

The Story Behind Multistar

The Story Behind Multistar


I've been exploring ideas for large out-of-order machines, such as MultiClusterMultiThreading (MCMT), Multilevel Instruction Windows, and Multilevel Branch Predictors, for years - actually since before I joined Intel for P6 (which was a single level OOO machine), and especially after P6, when I attended the University of Wisconsin, at which I did NOT get my PhD, and did NOT get anything published, especially NOT multilevel branch prediction, but where I gelled my MCMT ideas.

I took these ideas to Intel when I returned in 2000, and then to AMD in 2002.  Of course, I took only my UWisc ideas that were public to AMD, nothing from Intel.  I can't talk about what I did at either Intel or AMD, and it probably won't ever see the light of day. I am happy to see that AMD has announced that Bulldozer in 2011 will be an MCMT machine, even though they switched my definition of cores and clusters around. Even if AMD patents my ideas, they probably won't give me credit.

But anyway...  I left AMD in June 2004, and rejoined Intel in August 2004.  In between was one of the few periods in my career when my work was not immediately assigned to an employer like Intel or AMD.

So, I spent the summer surf kayaking at Oceanside, Oregon.  And, at the last minute, writing up these "MultiStar" ideas.   My goals were three-fold: 

(1) As usual, I just plain love computer architecture.

(2) I wanted to have something that I could start work on immediately if I decided to quit Intel and finish my Ph.D.   (The biggest pain about working at AMD was that I left behind 10 years of ideas that I had created at Intel, that I could not use at AMD.)

(3) Lastly, the idea of getting patents outside of a big company was attractive.  I have almost 100 patents through my employer; why not a few on my own?  Heck, if only I had patented the aspects of the P6 microarchitecture I invented at UIUC in my MSEE, such as my form of register renaming, HaRRM (Hardware Register Renaming Mechanism)...

So I wrote up MultiStar.  I had to go beyond any microarchitecture I had done at Intel or AMD.  I did not use any ideas that belonged to Intel or AMD.  I could only use ideas that were already public, or which I created new and fresh in the summer of 2004.  I had to invent new ways to do things that I had already invented once or twice before, at Intel or AMD.  I had to leave a few parts of the machine unfinished, because I had not invented new ways to replace what I had done earlier.

I called it "MultiStar" because I arbitrarily decided to make it an out-of-order microarchitecture with multi-level everything.  Multilevel branch prediction, I$ (easy), decodxactly the same documener, microcode, renamer, scheduler, register file, instruction window, retirement, datacache.  Multiple clusters. Everything.  I don't necessarily recommend multilevel everything as a way to build a machine, but, surprisingly, the ideas fit together remarkably well.  I think it could be built.

I was especially happy that I invented new ways of building a multilevel instruction scheduler and register file / operand bypass mechanism - solving problems that I had been trying to solve for years at Intel and AMD.  This solution acheives the sort of pleasing elegance that makes you feel confident you have it right. The time and place I invented this sticks in my memory (above the waves in Oceanside), like the time and place I invented the form of register renaming used in P6 (UIUC, Hwu's classroom, winter, pipes banging), and the time and place I invented Intel MMX (driving back from Princeton with Bob Dreyer, after the i750 was cancelled).

I wrote up multistar.  Emailed copies to Hwu and Patt, and a few others.  Joined Intel, disclosing multistar, all umpteen pages of it, as the "Intellectual Property Preceding Employment".

And, oh, yes, assigned multistar to an invention company to apply for patents. Using exactly the same disclosure as I provided to Intel. You can see the patent applications at the USPTO website, since they become public a short while after application.  Unfortunately, I was not able to work on the the patent applications after I rejoined Intel, since I did not want to risk contaminating them.

At the time, I thought that multistar was more than 10 years ahead of what Intel or AMD would consider building. Time will tell.


By the way:  I am quite pissed off by all of the people who say that single-threaded CPU microarchitecture has run into a power wall.  Yes, power is hard, and yes, performance does not go up linearly with number of devices.  Performance only seems to go up as the square root of the number of devices, so-called Pollack's Law.  But performance still goes up.  And power need not be linear in the number of devices.

As I am wont to say, the square root of an exponential is still an exponential.

I am slightly pissed off that saying this seems to put me in the camp of single thread OOO microarchitecture bigots.  I've been working on multiprocessor and multithreaded microarchitectures for years, again since undergraduate. Sure, I like using them to build SpMT, but I am also quite eager to use them to build mulithread systems. If you have parallel workloads.  And I have ideas how to make writing parallel code easier.  I like working on exascale supercomputer architectures with millions of processors and billions of threads.  I have been a loud advocate of highly parallel GPU-style SIMT Coherent Threaded microarchitectures.

I am NOT just a single thread OOO bigot.  I know how to make BOTH single threads and multiple threads run faster.

Single thread OOO microarchitecture ran into the power wall because Willamette was a stupid microarchitecture.  Emphasizing high frequency because it was a marketing gimmick, and because the Willamette microarchitects were not confident about how to build more advanced OOO. Single thread OOO microarchitecture ran into the power wall because the guys building Nhm were weaned on Willamette. And because Intel and AMD became reluctant to do anything that was not incremental.

Willamette had some good ideas.  Even replay, the cause of so much instability, can be used effectively, e.g. with transitive cancellation to prevent replay tornadoes.  But Willamette gave them such a bad reputation that ideas like replay may not be looked at again for 10 years.  (It's already been almost five.)

Actually, multistar is really quite incremental.  It applies a well known technique, multiple layers, to several microarchitecture datastructures.  Working out the details of how to do so is not necessarily obvious.

Multistar was one of the best ways I knew of the build large OOO machines in 2004, building on ideas in the public domain, plus a few weeks of new ideas.  It isn't even the best way I know how, although it does have some ideas that were new at the time. 

Of course, my ideas continue to evolve.

Minor updates to my Google Docs website

Added multistar microarchitecture thoughts from 2004 (that are NOT owned by Intel or AMD).

Added linked to my presentation on Coherent Threading GPU architectures, given at UC Berkeley ParLab in August 2009.