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User: PeterM+from+Berkeley

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  1. Intel's compiler doesn't always beat GCC on Intel C/C++ Compiler Beats GCC · · Score: 2

    Hello,

    I tried Intel's C++ compiler on a pentium 4 running Linux. (Yes, they have an evaluation verson of their compiler for Linux.)

    The results were disappointing on my own pet benchmark: the scientific simulation I use.

    The Intel C++ compiler produced code 2x slower
    than gcc. I used "naive" optimization flags
    like -O3, etc.

    PM

  2. Re:If you are already running it... on Serious Bug In 2.4.15/2.5.0 · · Score: 4, Informative

    I wouldn't do what this guy says.
    You're pretty much guaranteed to corrupt your
    filesystem this way. Probably nothing fsck
    couldn't fix, but still.

    Other posters have suggested that you use
    "shutdown -F" after running "sync",
    and rebooting into a NON-2.4.15 kernel.

    "sync" will write all the unsaved data to
    the disk, and "shutdown -F" will cause
    an fsck to start after rebooting.

    PM

  3. g++ icc on my own FP-heavy program. on Intel's New Compiler Boosts Transmeta's Crusoe · · Score: 2


    I tried Intel's C++ compiler on my own floating point heavy plasma simulation program. I tried some very high optimization flags, and that produced a binary which crashed.

    Using -O1 produced a binary roughly 1/2 as fast as a -O3 g++-compiled binary.

    Perhaps this compiler is a win on C code, but on C++ it sure looks like a dog to me.

  4. Re:Two problems... on More Details Emerge on AMD's Hammer · · Score: 2

    Actually, Hammer doesn't need OS and compiler support from MS. Hammer runs 32-bit code and existing software fast.

    It would HELP if MS had their OS and compiler support Hammer's extensions, but even if MS sits on its ass, that huge legacy market will belong to AMD.

    And what about the server market? Well, the server market is *much* more accepting of non-MS operating systems.

    I do not see lack of MS support as a certain sign of doom for AMD....

  5. Re:NUMA ... shudder .... on More Details Emerge on AMD's Hammer · · Score: 2

    Hardware-wise, multi-CPU Hammers will indeed resemble NUMA. Each CPU will be directly controlling its own set of DIMMS.

    However, from what I understood of the description, memory access should all be taken care of in hardware with no OS support. The CPU interconnects are supposed to make even remote memory transactions very, very fast, not much additional latency than to direct-accessed memory.

    Linux would therefore "need" no explicit NUMA code, and could improve things just a bit by setting CPU affinity of a process to the one which has the process in local memory, very similar to the CPU affinity code which is already in place for keeping a process on the same processor which has its data in the CPU cache....

    Maybe someone else who knows more can weigh in on this, but to me it looks like a small issue.

    PeterM

  6. Re:Sounds like the Argentine ant invasion in CA,US on Invasion of Invincible Ants · · Score: 3, Interesting

    I think you're probably right: eventually this monogenetic supercolony is going to get wiped out or severly damaged by some pathogen.

    I bet it'll be some fungus that likes to dine on them, or perhaps a virus.

    Efforts are already underway to introduce parasites and pathogens to control fire ants in the southeast USA, but I haven't heard of anything being done about the Argentine ant.

    The Argentine ant does a few things which are harmful, like wiping out native ants and herding and defending aphids (actually quite a large nuisance, leading to crop damage and reduced production), but they don't sting and if they live in/near your house in numbers, they'll wipe out termite colonies--with my own eyes I saw a termite colony in a treestump next to our house get wiped out.

    If you could train this ant to kill aphids, get out of sight when the lights go on, and stay out of your food, I think they'd be a great ant to have as a domestic partner to man.

    Think about it: no stinging ants, no roaches, no lice, no fleas, no termites, crumbs cleaned off your floor, all manner of insect pests attacked and eaten, and when the lights go on they disappear. Arguably better than any cleaning robot that could be made.

    Imagine the agricultural use: train them to eat aphids, scale, caterpillars and any other insect that moves (except bees). Guess what? You don't need insecticides anymore.

    These ants are amazing and I want them on MY side, with just a few little changes.

    PeterM

  7. Sounds like the Argentine ant invasion in CA,USA on Invasion of Invincible Ants · · Score: 4, Informative


    California is suffering a similar invasion of the Argentine ant. These guys don't sting, so they're not as bad as the fire ant.

    However, they do have some interesting features which is allowing them to wipe out native ants and completely dominate the CA landscape:

    1) Many queens per colony. In any ant vs. ant battle, the Argentine ant can usually bring far greater numbers to bear, and tiny as they are, they win.

    2) Tolerance. Apparently, only one colony of Argentine ants made it into the USA, in the beginning. All the daughter colonies are so similar genetically one US colony of these ants
    doesn't recognize another as an enemy. So every
    colony of Argentine ants in the US is the friend of every other colony. Or, you could say that ALL the Argentine ants in the US form a single supercolony.

    Fire ants are apparently similar in this respect, so there's a big supercolony of fire ants in the southeast US, and a big supercolony of Argentine ants in the West. Will one or the other supercolony come to dominate North America, or will they eventually form a stable frontier?

  8. Re:It can do what now? on New Semiconductor Coolers · · Score: 2

    You're exactly right on all the points you raise.

    The only way you'd get 700 W through a 1cm^2
    area is if you placed a highly conductive
    material on one side at a high temperature
    and another highly conductive material at low
    temperature on the other, (like two silver rods)
    and then supplied heat and cooling to the hot
    and cold rods.

    If the hot end were air and the cool end were air,
    you'd have to be blowing hot and cold air with
    hurricane force across the surfaces.

    PM

  9. People are already barcoded. on McNealy Calls for National ID Card Too · · Score: 2


    Just put your thumbprint on something. Presto,
    your very own barcode. Cannot be forged easily.
    Unique to every individual.

    PeterM

  10. I get install CDs from cheapbytes. on Do We Spend More On Linux Or Windows? · · Score: 1

    Cheapbytes will sell you Linux install CDs for
    about $3-4 + shipping.

    That's how I usually get copies of the latest RedHat, and so I've payed about $10 in the last 2 years for Linux, for personal use.

    For work use, I've caused to be bought several boxed sets, for probably $200 in the last 2 years. That's my way of supporting my distribution creator.

    PeterM

  11. This fits in naturally with SOI on Stretched Silicon Speeds Semiconductors · · Score: 2

    IBM is using Silicon On Insulator to make microchips these days. In an SOI process the silicon you actually make the transistors on is very thin, at most a few microns, and beneath that is an insulator, such as SiO2.

    If instead you do epitaxial Si deposition on another insulating crystal, perhaps sapphire, with a lattice slightly larger than Si's, you get the benefits of an SOI process *and* this improvement from a strained lattice.

    This is a real technical coup on IBM's part.

    As for diffusion, well, IBM can use dopants with lower diffusivities should this be a problem for part longevity.

  12. Spinoffs on NASA: Planetary Exploration, Or Better Coffee · · Score: 2


    I would rather spend less of my tax money on unmanned probes. I think I will get far more "spinoff" per dollar that way, without sending some poor people into space to deteriorate physically at best and die at worst.

    I think we'll get FAR more cost benefit from developing smart machines to explore Mars for us. We can turn right around and use these smart machines here, WITHOUT the expense of boosting a multi-year human habitat and life support all the way to Mars and back.

    Silicon survives in space better than people, after all. The only benefit of sending people instead of a probe is so that we can put footprints in Marsdirt.

  13. Tried it for 10 minutes. No SSL, AND it crashed. on Mozilla 0.9 Out · · Score: 2

    This was on my RedHat 6.2 box.

    Not only would it not read SSL pages for me (it just showed a blank page), it crashed on me while I was trying to poke around in the menus to see if there was a toggle to turn on SSL.

    PeterM

  14. Fission energy comes from fast fission products on Fission in a Box · · Score: 2

    The reason that fission energy is used to heat gas or boil water, which in turn is used to spin turbines for making electicity, is that fission energy comes mostly from kinetic energy.

    For example,

    n + U235 --> Heavy1 + Heavy2 + 2.4n + 215MeV

    where n are neutrons, Heavy1 and Heavy2 are two
    split parts of the U235 (Uranium 235) atom,
    and 215MeV is the energy released.

    Something like 90% of that is in the motion of
    Heavy1 Heavy2 and the neutrons (i.e., 180MeV of
    kinetic energy.) The kinetic energy of
    Heavy1 and Heavy2 is deposited very quickly
    in the surrounding fuel as heat. The neutrons take a little longer to slow down, but no one
    knows a way to directly convert the energy in
    fast neutrons into electricity.

    As someone else has pointed out, if you're
    doing nuclear fusion in a plasma,
    as in
    Deuterium + Helium 3 --> Helium 4 + proton
    you can convert the energy directly into
    electricity, because the fusion products are charged.

  15. How sure are they that they've found them all? on A Map to Nowhere? · · Score: 2

    If I remember right, one of the ways they found genes "fast" is by killing a cell and looking at what genes were active at that moment.

    However, what if--to use a computer analogy--
    those 30,000 genes are merely the "working set"
    of a much larger program?

    Put another way, what if there are a great many other genes which are inactive for the vast majority of the time, but which DO matter?

    Do they have other ways of finding genes
    than I described above, and have these methods been used to cover the whole genome?

    PeterM

  16. Self-contradictory military mind on NASA Prototype Plane Scheduled To Attempt Mach 5+ · · Score: 2

    Interesting, an example of the self-contradictory military mind.

    1) They want a bomber flying at mach 5 which will be "too fast to shoot down".

    2) They want a missile defense system capable of destroying both theater and ballistic missiles.

    Is it just me, or is this another proof of the
    oxymoron "Military Intelligence"?

  17. Why have offchip DRAM at all? on Single-Atom Transistor · · Score: 2

    They claim 1Tb on a 10cm^2 die. Let's assume
    1 transistor per bit (pessimistic).

    That's 1 x 10^11 transistors on a cm^2 die.

    Do you realize how much SRAM memory that translates into? Roughly 2GB, with
    enough transistors left over to have a CPU on the same die.

    WITH A CPU LIKE THAT...

    WHO NEEDS A MEMORY SUBSYSTEM?

    Just give the thing some I/O pins to talk
    to a bus!

    PeterM

  18. Userland recovery tools for reiserfs? on RedHat "Fisher" 7.1 Beta Out Now · · Score: 1


    Is anyone working on good recovery tools for reiserfs? Journal replays don't fix everything: sometimes disk sectors just go bad, and something like e2fsck can help mostly-recover the filesystem.

    It'd be a huge drawback to reiserfs if a bad sector took out the whole fs.

  19. Re:But they give you a great compiler on Slackware Now Available For The Alpha · · Score: 2

    Redhat 7.0 for alpha provides ccc and cxx with a "hobbyist" license, i.e., no cost for non-commercial and non-institutional work.

    ccc and cxx do indeed provide huge benefits over gcc/g++ on Linux/Alpha. They compile programs quicker and the resulting programs run faster.

    Licenses cost about $500, which is a reasonable price for boosting your alpha's speed by 30-70% or more.

    PeterM

  20. Re:What do they expect? on Global Warming Worse Than Thought · · Score: 3

    >Call for citations. Medieval Britain burned a lot of coal & I haven't seen any evidence that it damaged the ecology of the islands there.

    http://www.ucsusa.org/energy/brief.coal.html

    That is where I got the tonnage data.

    And Medieval Britain did NOT burn "a lot" of coal by today's standards. I mean, do you REALLY think that they burned megatons of coal per year? REALLY?

    Are you really ignorant of smog and acid rain and poor air quality today?

    >> (often strip mining) and produces hundreds of
    >> thousands of tons of toxic waste, much of
    >> which is toxic forever and not for 100k years
    > only

    > Ever hear of hard rock mining? (Hint: that's what the adults were doing in the movie ``October Sky".)

    I'm perfectly aware that not all coal is strip mined. That is why I said "often strip-mined."

    Hard-rock mining has its environmental impact as well: I admit it's not as self-evidently bad as strip-mining.

    >How many people die in mining that? Oh, & be sure >to ask around the Navaho & Hopi reservations -- I >hear a lot of folks living there died due to >years of mining uranium.

    I don't know. Why don't you tell me?

    263 people died mining coal from 1992 to 1997
    according to

    http://www.dol.gov/dol/opa/public/media/press/ms ha /msh97470.htm

    >> WORRYING ABOUT NUCLEAR WASTE WHILE CONTINUING
    >> TO BURN COAL FOR POWER IS UTTERLY MORONIC.

    > Elaborate. Or would *you* be accusing me of an ad hominem attack? Sorry, but I get these responses confused.

    That was not personally directed at you, but at our society, which has a very irrational way of balancing risks.

    It is STUPID to worry so neurotically about a possible nuclear accident when we're creating a worse in negative environmental impact to a nuclear accident by burning coal for power.

    Looking at the record of the two industries, it is coal burning which should be banned and nuclear power which should be promoted. Nuclear power has the *risk* of a terrible accident: coal mining and burning has a 100% probability of having a huge negative environmental impact.

    Even Chernobyl is nothing compared to the damage the USSR's dirty industrial complex has created in that country.

    The fearful attitude of the American public toward nuclear power is like a smoker fearing brain cancer from his cell phone. He won't quit smoking but refuses to use his cell phone! Even though he's 10000 times more likely to suffer an adverse effect from his smoking!

    >So we've been told. And the US government spent >millions of dollars & untold manpower to keep >_The_Progressive_ magazine from reporting >negative
    > details about nuclear power. Do you >think that we've heard about all of the near >misses, or can trust that the PTB learned from >these mistakes?

    Do you think you've heard about all the "near misses" with chemical plants? Massive chemical spills? Bhopal, India? Gasoline spills? You live with many much larger risks every day without giving it a second thought.

    If I had to choose between living next to a chemical plant, a coal plant, and a nuclear plant, I'd pick the nuclear plant every time--unless
    it had a graphite core! Naturally I'd like all of these things far from me, but of those three, which would YOU choose?

    >> MORONIC.

    > Excuse me. Are you talking to me? Or to people who share in your delusion?

    I'm accusing a society that is so utterly stupid about calculating risks. That kind of thinking is moronic. It is imposing high costs to ameloriate microscopic risks while ignoring daily practices which cause huge amounts of real damage every day.

    PeterM

  21. Re:What do they expect? on Global Warming Worse Than Thought · · Score: 3

    Nuclear waste lasts 100,000 years, but toxic
    waste from coal-burning lasts forever.
    It doesn't decay, ever.

    A 500MW coal plant consumes
    1.4 million tons of coal. When you burn
    this coal, you get:

    10K tons of sulfur dioxide. (acid rain)
    10k tons of nitrogen dioxide. (smog, acid rain)
    3.7 million tons of carbon dioxide (warming)
    (note: the O2 in C02 comes from the air)
    .125M tons of ash
    .193M tons of sludge
    (the ash and sludge contain mercury and other
    heavy metals which are toxic, including
    more radioactivity released into the
    environment than a nuclear plant.)

    So which would you rather have:

    1) an enviromental disaster of a coal plant,
    which causes 1.4M tons worth of mining
    (often strip mining) and produces hundreds of
    thousands of tons of toxic waste, much of
    which is toxic forever and not for 100k years
    only

    OR
    2) A nuclear power plant, which doesn't require
    the mining of 1.4M tons of raw materials,
    and doesn't produce 200k tons of toxic waste,
    but rather *15* tons of high level waste,
    *35* tons of mid-level waste, and *100* tons
    of low-level waste.

    WORRYING ABOUT NUCLEAR WASTE WHILE CONTINUING
    TO BURN COAL FOR POWER IS UTTERLY MORONIC.

    You also bring up Three Mile Island and Chernobyl.
    Did anyone even *die* in TMI? No. How many
    people die every year from breathing in all
    the toxic waste from burning fossil fuels?

    And as for Chernobyl, we're not stupid enough
    in this country to use flammable graphite to
    moderate the reactor core. *our* worst
    nuclear accident killed no one and didn't even
    *injure* anyone.

    How many COAL MINERS die *every* year?

    WORRYING ABOUT THE SAFETY OF NUCLEAR POWER PLANTS
    IS MORONIC WHILE WE'RE STILL MINING AND
    BURNING COAL.

    MORONIC.

  22. Nuclear plants produce net energy on Global Warming Worse Than Thought · · Score: 2

    Nuclear plants absolutely make more energy
    than they take to make! No utility would
    ever CONSTRUCT one which didn't. I
    mean, think about it: 30 years of continuous
    1GW operation. Let's say $.02 per KW-hour.
    (We pay $.11/KW-hour now retail).

    That's $5G just to build a plant, on *top*
    of all the other capital investment.

    Now, with the burden of changing government
    regulations on operating nuclear plants and
    mid-construction design changes, it might well
    *cost* more to build a nuclear plant then
    you get out of it.

  23. Re:Nice way to screw the post office on Spammer Gets Spammed · · Score: 2

    I don't see how this would necessarily follow.
    You put the sparklies in the envelope. The
    envelope stays closed until it gets to the
    junk mailer?

    Then, when the junk mailer opens it, it gets
    all over HIS sorters, not those of the post
    office?

  24. Diamond crystal is not the only structure of C on Dawn Of The Diamond Age? · · Score: 1

    The guy's premise was placing carbon atoms
    wherever he wanted it. You could use diamond
    crystals for compressive loads and use carbon
    nanotube fibers for tensile loads. Given a
    composite material of both structures of carbon
    I think you could make a very strong *and*
    flexible *and* non-brittle building material.

    As to whether this material would burn or not...
    I don't know.

  25. And in other, far less signficant news.... on First Ever Pitfall Perfection? · · Score: 2

    1) Israel has granted Palestinians full citizenship and representation in government, and the Palestinians have agreed that full equality and participation in goverment is fair and just.

    2) IBM has perfected holographic memory: data
    crystals which consume now power, have an access time of 1ns, and a capacity of 1000TB are in stores near you.

    3) Impartial recounts by news services in Florida shows that Gore actually DID win by 350 votes. Bush has agreed that this clearly displays the will of the people and has stepped down in favor of Gore.

    4) Slashdot has instituted a news story moderation system. Now the readership can judge which submitted stories are worthy instead of being fed whatever the slashdot editors find amusing at the moment.