Slashdot Mirror


User: nwf

nwf's activity in the archive.

Stories
0
Comments
482
First seen
Last seen
Profile
(view on slashdot.org)

Comments · 482

  1. Re:Duh? on More Interest In Parallel Programming Outside the US? · · Score: 1

    Most problems do not parallelize to large scales. Name a single real world problem that doesn't parallelize.

    Obviously this depends on your definition of "real world." Many simulation problems in the physical sciences do not scale well, since each cell's step is dependent on all other cells. There are approximations that try to reduce this dependency, but approximations are never perfect. However, one may discount these as not "real world" since most people don't simulate low-level physics and such (and these aren't NP complete either, which are sometimes parallizable. E.g. when you double your problem, it may cause an 8x increase in work, but that may be parallizable. You can parallelize the traveling salesman problem which is NP complete according to wikipedia.)

    There are much larger class that don't scale to very large scales. As I recall from my parallel programming class, after about 64 or 128 processors, shared memory breaks down due to limitations on bus interconnections needed for cache coherency. You can emulate shared memory with MPI and things, but it's WAY slower to the point of being useless for applications without a high degree of spatial locality. In fact, all but the embarrassingly parallel don't scale linearly due to shared memory and synchronization, so I've yet to see many non-trivial problems that scale to massive levels well. I'm talking 1000 processors or more (which is where we are headed, it seems, since they can't increase processor speed much. They have to do something to sell us new CPUs.) You may double the processors but only get a 20% speedup. One of many examples after 15 seconds of Googling, here Another one here where they doubled the processors and only got a semi-logarithmic increase in speedup (very common from what I recall from class.) Database updates won't scale well, since fundamentally you need some concurrency control to ensure ACID and that can't scale forever.

    So almost anything can parallelize, but not everything can do so well. Sure it may be faster, but not nearly as fast as doubling the CPU speed. For many systems going to 2 or 4 processors will help a lot, since people also use multiple programs or services in the background, but that's low hanging fruit. (And welcome, I use dual core CPUs and find it helps for that reason. But 1000 cores? I don't think that will help do any common task for an average user.)

    So, basically, I think we are all right. It's generally faster with more CPUs, just not much faster in the higher cases and we'll reach a point of diminishing returns. Is it worth it to double the cost of a CPU for a 5% speedup? For some, I'm sure, but eventually it just don't be worth it to increase the number of cores. I used to work with people who made parallel simulations and they'd spend years getting an application working on a specific architecture. They'd be ecstatic when they got a 10% speedup. Not really practical for most consumer products.

  2. Re:It's all the wording for HR on IT Labor Shortage Is Just a Myth · · Score: 1

    The company I used to work for, a large federally funded research organization, hired tons of people right out of school. Pay was lower than average, but you could easily get tons of experience doing anything you wanted. In my case, I moved on after many years to a new job that paid a ton more, based on that experience. In addition, while in school, take an internship. Thousands of companies do this, and it's experience you can put on your resume. I've interviewed at least 500 college students for positions, and generally I hired ones that had a reasonable experience at summer jobs and had a passion for CS (very easy to weed out.) Many did move on after a few years to higher paying positions, but they did get great experience with us. Microsoft, while evil, will hire about anyone from the looks it.

    In fact, while interviewing, I'd always see tons of companies hiring recent grads. Part of the trick is where you got a degree. Sad, but true. We'd completely ignore people with degrees from many universities and colleges since their degrees just aren't very good.

    Now I work at a very small company, and we just don't have the time to train people, so we pay more and get excellent people.

    I think that as a company grows, it becomes less sensitive to how much it indirectly costs to have a high turnover and pay lower salaries and get the people that that entails. While on some projects for various federal agencies, I'd see that all the time.

  3. Re:Math Forfront on Mathematician Solves a Big One After 140 Years · · Score: 1

    Calculus also birthed differential equations, which are used all through engineering, and even the Fourier transform, without which we wouldn't have cell phones or MP3s. But, abstract algebra is a good example, but I haven't used it much since college. And number theory is the basis of modern cryptology.

  4. Re:wow on Mathematician Solves a Big One After 140 Years · · Score: 3, Funny

    But can you prove it? There's got to be a limit somewhere here...

  5. Re:Maybe Apple should... on Paypal Advises Users To Stop Using Safari · · Score: 1

    Or more to the point: why waste time mousing when Macs all come with keyboards? Command-W is still the fastest, and it works across almost all applications, unlike every other OS I've used where nothing is standardized. Not that I don't use Windows and Linux daily, mind you...

  6. Re:Math Forfront on Mathematician Solves a Big One After 140 Years · · Score: 2, Interesting

    I think that rather than math becoming applicable, it actually enables discovery and enables people to think about problems. Without many seemingly uselessly arcane topics, we'd be back in the 1900s. Calculus comes to mind. Heck, physics these days seems to be nothing more than experimental mathematics with string theory and the like.

  7. Re:Sounds like he's been reading slashdot... on Woz Dumps on MacBook Air, iPhone, AppleTV · · Score: 1

    I wish Apple luck with the Air, but as someone who has owned at least 6 different PowerBooks and now a Mac Book Pro, I'd never get an Air. The lack of Ethernet and a non-replaceable battery are deal breakers for me. Apple has generally been very good at balancing features, cost and easy of use. Not here. Sort of like the Apple TV. What's the point? Both are so limited as to be nothing more than a toy.

  8. Re:And? on RoadRunner Intercepting Domain Typos · · Score: 3, Insightful

    Yea, I noticed this as well and also didn't think something so trivial was news worthy. Now I'd like it if they also re-directed typo-squatters domains as well. That would be a public service, especially anything in the .cm TLD.

  9. The new order on Microsoft Says Not All Ad Clicks Are Created Equal · · Score: 1

    This appears to me to be their first steps at integrating advertisement tracking into the operating system. How better to properly track what ads people seen in order to properly compensate clients? This is an area where Google can't compete, but Microsoft can since they own the OS. Sure it won't work under OS X or Linux or FreeBSD, but when sites require a "compatible" browser that does "proper" ad view tracking (using their parented technology) to even view the site, you'll have to use IE to view anything. Pretty sneaky.

  10. Re:No offence, on A Mythbuster's Biggest Tech Headaches (and Solutions) · · Score: 1

    However, the iPod interface allows you to get L+R without ANY electronics and, more importantly, no power.

  11. Re:As long as laws like... on LAN Turns 30, May Not See 40? · · Score: 1

    And neither will anyone working with finances or credit cards. Specifically, PCI doesn't allow for WANs. You must have a firewall and web server in a DMZ.

    People who say LANs will go away have no idea what they are talking about. NAT may go away, but LANs will never go away. It's just way too cost effective to aggregate your traffic into one higher speed WAN link. I can transfer files between computers in my house via gigabit Ethernet, but if they all had to go out to te "internet" first, forget it on my 2 Mbps uplink. Granted you could run each into a port on a WAN router, but that's expensive and not really helpful. A switch with a higher-speed uplink port is really all you need, and that's a WAN.

    Similarly, wired networks aren't going away for security and speed reasons as well. I'd wager my gig Ethernet can out pace any fance 802.11n connections, especially between multiple computers on the same WLAN. I can get full one gig between every port and my switch was less than $300 for 24 ports.

  12. Re:No offence, on A Mythbuster's Biggest Tech Headaches (and Solutions) · · Score: 3, Informative

    I'm with you -- mini and micro USB is much more standard than the iPod and there's no reason Apple couldn't have used USB instead. It would've possibly cost more, sure, so they did something proprietary like everyone else.

    In fact, there is. Getting L+R audio and video can't be done via USB and plug it into a stereo and/or TV with minimal electronics. Plus, there are ways to remote control the iPod via the connector, although I suspect that could be done via USB pretty easily.

    I don't think they even had micro USB when the iPod came out, either.

  13. Good for them! on Smartphones Patented — Just About Everyone Sued 1 Minute Later · · Score: 4, Insightful

    I say, "good for them!".

    Perhaps this is just what we need to make congress re-think our amazingly incompetent patent office. Clearly, computers can do all of this stuff, and a cell phone / PDA is just a hand-held version of a computer. Nothing really novel, but that never stopped the patent office.

    Unfortunately, I missed my chance to patent patent trolling and further patenting the patenting of patent trolling. Etc.

  14. In my experience... on Followup On Java As "Damaging" To Students · · Score: 1

    There are still universities that are not dumbing down their curriculums. Carnegie Mellon is one of those. As a former CS technical recruiter for a large organization, there are definitely differences in degree programs. We generally got excellent folks from the top CS programs (MIT, CMU, Stanford, U of Illinois, etc.) However, there were several where we needed to be careful and many others we wouldn't even consider hiring from. In general, a degree in IT/CIS is useless whereas a nice theory-based (and math-based) CS degree is very useful.

    Regardless of where folks came from, I did notice a major shift in preparedness to enter the workforce across disciplines and schools. Kids were spoiled and are shocked to find that the real world "suffers" from some novel concepts:

    1. You won't always win. This isn't T-Ball.
    2. There are people who are smarter, having more impact, and who can apply their skills better. ALWAYS.
    3. You will fail. Get over it. Learn and move on. It's not the time for a melt down.

    And a really major issue is emotional stability. I can't imagine how some folks got through school. It's a tough world, and you need to be tough enough to take rejection, disappointment, failure and outright people being mean and selfish. I've seen people cry at design meetings where their designs were being critiqued. And this was in a group that was being particularly nice, IMHO. Think emotional intelligence. Oddly, I found folks with electrical and computer engineering to be more emotionally mature for some reason vs. pure CS. (And don't even get me started on IT/CIS degrees.)

    To the point of the article, I think Java is an excellent language that has made me much more productive as a developer. However, I know how the data structures work and the low level implementations. I've had many classes in low-level database development. I spent my summers in high school in 6502 assembly. I can see how using a high level language first doesn't encourage you to really understand computer science. To that end, I think people should be taught in C and have to do assembly. In fact, I had to do both assembly, C, LISP & Scheme, Prolog, SML, C++ and other languages just to get a degree. This was very valuable. That and implement part of a CPU in Verilog. All very helpful. Theory comes first, then we abstract some of the lower level things away. Now that you know how a hash table works, welcome to Java or STL or whatever.

    I do agree that dumbed down curriculums are producing a bunch of nearly irrelevant "graduates." But, look that most universities have to work with. High Schools are so dumbed down as it is, what are you going to do? My HS I had to take 4 years of science, 4 years of math, 4 years of English, 4 years of history, and 2 years of a language. How can you even think about pursuing a technical degree without trigonometry (to say nothing of pre-calculus) in high school?

    So, while university curriculums are being dumbed down, the real problem is the primary education. I know many teachers and they constantly complain about meetings with parents who try to argue their kid's grade up. (My aunt quit because of it.) "This will prevent them from getting into XXX University." Well, you know when tests are coming, how about trying to study? Cut back on the 100 sports/music/art classes. Can't do the academic work? Well maybe MIT shouldn't be your first choice.

    However, these trends are cyclic. We'll get some dumbed down and eventually people will be outraged (think 50 years ago with Sputnik and the mass panic over our science and math education.) But, we in the US can't plan ahead, so we'll just keep going until we are so wasted and far behind, we'll then spend tons of money getting caught up.

  15. Re:Slick! on Comcast Promising Ultra-Fast Internet · · Score: 1

    Basically, when you request a VOD stream, you send the request to the system from your cable-box where they create the session, and create a one-on-one video stream on a edge-QAM on your node.

    And if you have a QAM tuner, you can (at least I was able before I dumped Comcast) tune on other people's PPV shows. You can seem them pause at the parts with naked women and rewind. So basically, they are indeed just unallocated channels just like everything else. VoD doesn't really stream, it broadcasts. They may be able to limit it by node or larger aggregation of houses, but nothing better than that.

  16. Re:Upload bandwidth? on Comcast Promising Ultra-Fast Internet · · Score: 1

    Cisco Systems Inc. is demonstrating a DOCSIS 3.0 modem that would let operators support downlink speeds of 160mbps and uplinks of 120mbps

    Which is likely shared bandwidth per node, which can serve quite a few houses. That's the problem they are facing now. They are severely bandwidth limited, and while 10x will help, it's not going to compete with FiOS. Certainly not in my area where at least 7 Comcast technicians verified I was only getting 512 down and 384 up. That's it (paying for 5 Mbps down, mind you.) I dropped them and moved to FiOS where I get 15/2 for $35/mo (part of a package.)

    If it's not their network infrastructure that will kill them (aggregating many houses on a single node), then surely their customer service will. After being promised by a manager he'd personally handle our issue and call me back within 48 hours and, let's see, it's been a year now, nothing from that manager. Plus, they STILL charge for cable modem rentals. I don't need that now.

    I think their DOCSIS 3.0 is just talk, it will be many years until we have it available in our area. They just don't want to spend on infrastructure when they can milk most people who have no choice. Those that do, they figure, "who cares, they are in the minority". $45 for 5 Mbps download in 2008? Please.

  17. Re:Don't have time to read your homework on Your Worst IT Workshop? · · Score: 1

    It has been my experience that the technical teachers who do the UCLA extension programs are great. Unless you are in the Los Angeles area that probably doesn't do you much good.

    I took one of those a while ago, a week long deal. I was impressed! The instructors generally did care about their teaching and the material. They were generally high quality, but as I recall, the week long class was rather pricey, but worth it since it wasn't my money! :)

  18. A List on $360M Patent Suit Over iPhone Voicemail · · Score: 3, Insightful

    Yes, seeing a list of things in a list format is so amazingly original. Just add "voicemail" and, sure it's patentable! I've been using internet-based "visual" voice mail for like 10 years. Octel VM systems come with a web option and have done so for at least 8 years. This patent, filed in 1977, is just being enforced now? Seems a good case for being invalid just based on the fact that they ignored all infringers until now. I skimmed that patent (http://www.freepatentsonline.com/4117542.html) and I'm at a loss to see how it applies. They talk of being able to speak letters a numbers. Specifically, under "Talking Phone Book" it can read your phone number from an address book as well as displaying it. (a) not rocket science, and (b) not what Apple's product even does. Looks more like a patent on an electronic address book.

  19. Re:Beh. on PS3's Back-Compat Loss Explained, Analyzed · · Score: 2, Funny

    Not me too!

    I own a PS2, but I want to get another console. I really only have room for two (currently a PS2 and XBox.) If the PS3 isn't backwards compatible with all of my PS2 games, then I won't be getting a PS3. I'll likely get a Wii.

  20. Re:OpenStreetMap? on Do You Recommend Google Maps API or Microsoft Live Maps? · · Score: 3, Informative

    Even though it is not complete

    I'll say. The entire city of Philadelphia is missing, and it's not exactly a small city. In fact, looking at the eastern US, it's pretty much useless at this point. Alas.

  21. Re:Interesting excuse ... on MMO Bans Men Playing As Women · · Score: 2, Funny

    That was my first thought.

    However, since I know I've met a good deal of people whose gender I couldn't determine, I'm wondering just what one needs to show on a web cam. Perhaps this is really a way for the Aurora guys to find dates who aren't 45 year old divorced males.

    Is this not a ripe opportunity for a "special" quote from SNL's Pat?

  22. Re:Never heard of it before now on Why AnywhereCD Failed · · Score: 4, Insightful

    Indeed, it looks just like a domain squatter site. When I first went there I though it was already gone and replaced by an advertisement site.

    Tip for potential businesses: don't make a site whose business model relies on tech savvy people look like a site tech savvy people are trained to ignore.

  23. Re:C++ long-in-the-tooth? on Firefox Working to Fix Memory Leaks · · Score: 1

    Java has automatic garbage collection and many applications still leak! Eclipse is a good example. I do Java Servlet development using Eclipse and WST. I can't do serious development for more than about 6 hours without Eclipse running out of RAM and promptly either freezing up or exiting. GC is no panacea. Sure it can make some things easier, but if the programmer has the code hold onto things that will never be used, GC won't help.

    Another example: at my previous job we used Java to create applications (no web stuff, just plain CLI apps.) GC became the problem because of the high allocation rate. Rewriting in C++ where we used smart pointers improved the performance 2-3x, mostly owing from the lack of GC and copious use of stack-based objects. Memory leaks were few and far between for us owing to a good architecture.

  24. Re:Not really bothered on HMV Canada Cuts Music CD Prices · · Score: 1

    Yet you complain about the cost of things every bit as much as we do. Doesn't merchandise in the UK have VAT already added? We don't, and one gets to add sales tax along with a rather high federal income tax, so CDs should cost much more in the UK than in the US. Personally, if a CD is more than $15, I refuse to buy it no matter what. I've never purchased one for over $15 and never well. I use to buy 2 CDs a week on average, but when the prices jumped to $18+, I buy maybe 1 per month on sale.
  25. Re:Credit Freeze = Relief on Credit Industry Opposes Anti-ID Theft Method · · Score: 1

    My insurer didn't use my credit "score". They calculate another number based on risk, which can include numbers of current and past credit cards (even with zero balances, which is all I have), the number of times you refinanced your mortgage, and even the lack of using credit. They don't disclose how they calculate it, but it's known that if you have 2-3 credit cards, it's better than having either zero or more than 3. (At least out here.)

    I came from another state that prevented insurers from using any credit history, which is how it should work, IMHO.