Part of the problem is that the marketing company's lite-brite boxes were unprofessionally made. There are wires and batteries hanging out the side; it has that look and feel of "bombs" you see in movies (like the ones with the stupid "I'll let you know when I'm going to blow up" 7-segment LED display countdown)... and if bombs look like that in movies, then they *must* look like that in real life, right? If they had just made their little LED boxes to have the same size, shape, color, etc. of the other normal traffic signs/signals, that is do a professional job, then at worst people would have just thought that someone had hacked an existing sign (it's not like most people can precisely remember the exact number of signs/signals at every bridge, overpass, etc. they drive past on the way to work).
Those signs totally look like some crap that some middle schoolers would throw together at the last minute for a "science" project (no offense intended to you middle schoolers out there who read/.; I should perhaps have said average or typical middle schoolers).
Ditto the first responder. ISA-goop matters not very much. Modern x86 processors (Intel or AMD) translate the x86 goop into relatively clean RISC-like operations. From that point of the processor and onward, the encoding/decoding warts of x86 don't matter. Almost any half-way sane ISA (and that's a generous "half-way" as it includes x86) can be decomposed into RISC-like operations. Several years ago when anybody cared about Itanium, Intel even had a paper published in an ACM/IEEE conference on how to implement a really aggressive out-of-order Itanium processor that basically decomposed the EPIC/VLIW insts into a bunch of micro-ops (brekelbaum et al., ACM/IEEE Intl. Symp. on Microarchitecture, 2002).
The cost at the end of the day is a little extra logic (not trivial, but not worth abandoning backwards binary compatibility over) which means some power and area overhead. Not a big deal.
The console makers don't always lose money on the hardware. Typically, they lose money on the first few batches, and then as manufacturing gets cheaper they eventually break even and then even start to make money. The original XBOX was not able to really capitalize on this because MSFT did not own a lot of the intellectual property in the hardware. That's one of the big differences with the 360: they own the IP for the triple-core PPC processor (even though IBM's fabbing it for them), which means improvements in semiconductor manufacturing (Moore's Law) --> reduced hardware costs --> profit on the hardware in addition to licensing fees on software.
The amount of money that MSFT makes on xbox games is also not nearly as much as you might think. The $50 you pay gets divided many ways from the brick-and-mortar stores all the way back through the supply chain to the developer and back to MSFT themselves. If they got $5 per game (which is probably too high), their 11 million units of Halos 1 and 2 would only pocket them $55M (the 11M units figure is about a year old now, and also includes the PC version).
The inquirer speculations are indeed useless, because they'll post fifteen articles on fifteen different possible outcomes. Then after the fact, they'll point to the one article that got lucky and say "See? We told you so!" without bringing any attention to the other 14 that were totally off the mark.
It's like someone buying every combination of lotto numbers and then saying, "Look! I always win!"
I was just in Germany last week, and I saw that they sold gas with an extra 4/10th of a cent per liter instead of the usual 9/10th. I totally didn't understand why they didn't bother with just going with 9/10th.
The difference is that in the tri-state area, it's more of a capacity problem. If there was some optimal way for people to drive (in terms of aggressiveness, politeness, lane changing decisions, speed, etc.), I would expect that it wouldn't make too much of a difference to the traffic problems. In Seattle, a large portion of the congestion is not due to road-capacity issues, but due to driver behavior.
Driving in the NYC area, if I hit bad traffic, I just shrug my shoulders, find a good radio station, and accept the situation. It's far more frustrating in Seattle because it doesn't have to be the way it is!
I lived in CT for a while, and would drive down to NYC on weekends (often on friday nights when traffic is pretty bad), but if you learn the routes, stay away from the GW bridge, have an ez-pass ready to go, listen to WCBS/880 for the traffic reports, and didn't get to NYC at 5-6pm, it usually wasn't too bad. Otherwise I'd take a Metro North train into GCT and subway it from there.
The other difference is that in NYC, you have Metro North, the NJ Transit trains (and buses), the PATH, and the MBTA. At least if your starting and destination points were reasonably close to an appropriate station, you could choose to take public transit. The public transit in Seattle is really weak (basically your options are buses or buses). So for the most part, everyone ends up driving.
The way I see it is that in NY/NYC, the roads/drivers are more like fully-associative caches. You can get mapped to any cache line, and increasing capacity has direct benefits. In Seattle, the roads are more like direct mapped (or at most *very*-lowly set associative) caches where drivers are always fighting for the same couple of cache lines. Increasing the capacity has limited benefits in this case.
OTOH, if the drivers didn't drive slowly in the left lanes, then this crazy aggressive driver wouldn't have to tailgate, switch lanes, cut people off, etc. The "me first" philosophy can have bad impacts on traffic, but that's a smaller problem when compared to the "who me?" drivers out there that don't even realize they're causing a problem in the first place. There are those drivers who tail gate, flash their brights, and honk at you to move over when you're driving slowly in the left lane, and I applaud their aggressive behavior. NY drivers are a bunch of aggressive, crazy, tail-gating, horn honking, assholes, but I would so rather drive with them and be an asshole with the rest of the assholes, than to drive with all of the appendixes** here in Seattle because the NY way is so much more efficient (banning non-hands-free cell phones in Seattle (like in NY) would also be a blessing). I'm not condoning road rage, but don't confuse aggressive driving with road rage.
** I chose the appendix because it's a useless organ. You might not like the anal sphincter because it's smelly and expels feces and flatulence, but it does serve a vital purpose.
Don't know why the parent post was moderated down, but...
it's totally true. I've driven for many years in the northeast, and generally people follow this rule. Living here in Seattle, it's very frustrating to drive because there are often really bad traffic jams at non-peak hours where roadway capacity is not the issue. On an n-lane highway, you only need n morons who drive at the same speed next to each other to make a mess out of traffic (and it happens all of the time). Not even considering the time and cost, adding additional lanes is an ineffective and poorly scalable solution in Seattle without first changing the behavior of the drivers.
The other problem is the fact that there are a lot of oblivious drivers who just don't pay attention. I live downtown near the marketplace, and I've seen plenty of day dreaming drivers casually fly through red lights without slowing down**, and even the occasional idiot driving the wrong way up a one-way street. Such driving skills (or lack of) do not translate very well to the highways. Add to this plenty of other problems such as people who can't merge onto a freeway and then *stop* at the end of the on-ramp, thus making it impossible for anyone behind them to merge either (and part of this is people who happen to be in the right lane not slowing-down/speeding-up to make room for the would-be merger).
As another poster mentioned, moving over is in fact the law. I think if the cops simply started ticketing people for slowing down traffic when driving in the left lanes, a good amount (obviously not all) of the traffic problems in the Seattle area would be taken care of (and it also provides more money in the form of ticket fines, and reduces pollution due to better fuel efficiency, blah blah...).
Another odd phenomenon is that besides the HOV lanes being underutilized, so is the rightmost lane! I guess everyone thinks the right lane is only for "slow" drivers, and of course everyone thinks "*I*'m not a slow driver", and so the second they get on the freeway, they hop over a lane regardless of the traffic conditions. This immediately results in all n-lane freeways having an effective bandwidth of an (n-1)-lane freeway. For those of us who pay some attention and have even the remotest capability to perform dynamic routing, the rightmost lane is (sadly) frequently the fastest way to go.
I just got back from a trip to Germany where I drove on the autobahn for the first time, and the reason everyone can drive so fast (besides it being legal to do so) is that everyone does in fact "stay to the right except to pass". On an unrelated note, if you ever rent a car in Germany and like to drive fast, pay the extra of couple bucks (I mean Euros) to upgrade to something with some juice in it. The VW Lupo I got was gasping at 160km/h (100mph), and there were plenty of cars just *blasting* past us.
** and I don't get it why people tell me I shouldn't jaywalk in Seattle when you've got to be watching for clueless drivers regardless of the traffic signals. Jaywalking is like cars making a turn on red. You don't have the right of way, but if the coast is clear, then proceed with caution. Sorry, just a rant from someone who lived in Manhattan for four years where people would even go as far as doing multi-phasic jaywalking: when the coast is clear in one direction of traffic, proceed to the double yellow line; proceed to other side of street when the other direction of traffic is clear. I've seen a dozen or more people standing along the double yellow line on third avenue (downtown where it's two-way) with traffic zipping around them on both sides, waiting for the "2nd-phase" of the jaywalk. It all comes down to the same thing. You've got to be paying attention.
I (physics undergrad) use a biro and a pad of budget paper for notetaking.
speaking of budget, I used to just take stacks of printer paper (often reams just sitting around the printers in computing clusters) to class and write on that. Add a 3-hole punch and a 3-ring binder, and you're set. If you're worried about the "stealing" aspect of looting the computer paper, I know others who would just take paper from the paper recycling bins next to the printers.
I prefer Extra Fine blue Pilot rolling ball pens, although they will occasionally pee ink on your fingers.
I haven't tried taking notes in class on a laptop, although I bet the constant clacking of someone typing would bug me after awhile.
It will depend on your studying/learning style, but for me, taking a digital picture of the black/white board doesn't work in actually learning the material. I learn much more efficiently by actually copying stuff down on paper since the trip from eyes to hand forces the information to visit the brain at least once. The other advantage is that taking notes (or doing anything quasi-active) helps in keeping you from nodding off after pulling one or two all-nighters. (I had a friend who took a very different approach: he drank a lot of water before class and having to go to the bathroom really badly would keep him wide-awake.)
Others may prefer to just sit and listen to what the prof has to say and rely on the class notes and/or textbook. This doesn't work for me, but I found it to be very effective to team up with someone who learned this way. You've got all of the notes and when you can't remember what they mean, your partner will be able to interpret them for you. And sometimes your partner will need your notes to jog their memory to recall what was taught in class.
This strategy was actually *necessary* with one of my college profs because he wrote so fast (chalk was literally exploding against the blackboard) that you had to write as quickly as possible to transcribe everything from the board to paper. You were writing so quickly that you didn't have the time to digest any of it, so you needed someone else who was actually paying attention to the content to tell you what all those little greek letters and e^-jwt's meant. And for this class, a laptop would have been useless as I don't think I know anybody who can type in boardfuls of matrices, fourier-transforms and equations for chebyshev filters that quickly. Maybe a PDA would've worked in this context, but I haven't tried so I can't say.
Actually, it doesn't matter that much whether you can get from the `zero' state to the `two' state with or without going through the `one' state first. Even in current processors, interference (inductive coupling), ground bounce, and other effects may cause what should be a `zero' to bounce up into the voltage range that would make it a `one'. That's one reason why the processor uses a clock. It doesn't matter what states the signal goes through so long as it has settled down to the correct voltage by the time the clock ticks and you sample the voltage (well, less the setup time of the latch...).
As mentioned by a comment a few posts down, they used to use base ten in machines (BCD = binary coded decimal), where each base-10 digit was encoded with a 4-bit binary value. Besides the increased complexity of base-10 arithmetic circuits, since each digit uses four bits, there's 6 possible states that aren't utilized. So for example, with two BCD digits, you can represent from 0-99 in BCD, but if you used those same eight bits in binary, you could represent 0-255. I think that's what people may be talking about when they say binary is more "efficient" than BCD. Otherwise from an information theoretic perspective, I don't think one unit is any better than the other (it would be like saying using "kilograms" is more efficient than "grams" or "milligrams" or even "slugs").
IBM didn't do it first. I lived in Manhattan from 1994-1998, and I saw spray painted ads on the sidewalks back then (and it was certainly *not* chalk!). That's not to mention all of the other crazy stuff that people paint on the sidewalks. (I don't know if it's there anymore, but there used to be painted footsteps that went on for blocks in the east village, and then a few weeks or months later, someone painted tools (yeah, like hammers and wrenches) along side the footsteps.) I think the first ad I ever saw painted on a NY sidewalk was from a sneaker company or shoe store, but it definitely wasn't nike.
Reminds me of the SNL skit with Guiliani which was a fake commercial about his new crack down on graffiti. If they saw your tag on a wall or somewhere, a special police anti-graffiti division would spray paint the word "sucks" under your tag. (and for multiple-time offenders, they'd have a special police artist paint "sucks" in the same exact style as your tag.) It'd be funny if someone painted or even just sharpie'd "sucks" onto all of the butterflies.
In "Introduction to Algorithms, v1" (CLR), I recall a little snippet where they mention that 10^80 is approximately the number of particles in the known universe. It's a pretty big number.
Jim Smith and Guri Sohi have a pretty good overview of how superscalar processors work. You can pull a cached version off of citeseer at:
http://citeseer.nj.nec.com/35243.html
If you want to get a better feel for the complexity (at the transistor-and-wire level), you could try:
http://citeseer.nj.nec.com/palacharla98complexit ye ffective.html
This paper is pretty technical, but you don't really need to understand all of the equations to get the gist of it. They're also a few years old now, but still relevant. If you understand how the circuits are organized, and that complex circuits and long wires are expensive (in terms of slowing down the clock cycle), then you can get a decent feel for how complex the proposed register virtualization might be to implement in hardware.
Other posters have commented on how clock speed is not the bottleneck, but it's actually the caches, buses, memory bandwidth, memory latency, etc. This really depends on the application and what you're doing. BUT, just because X isn't the bottleneck, it doesn't mean you have free license to tinker (i.e. slow down) X by a huge amount. Adding a slight bit of extra delay to X can easily make X into the new bottleneck. Removing bottlenecks is really difficult because as soon as you remove one, five other things are now the bottleneck, and you can't get any (or much) further improvement until you remove *all* of them. (The team only goes as fast as the slowest member, a chain is only as strong as its weakest link, yadda yadda yadda...)
And then there's a myriad of other issues such as design complexity, added complexity in test and verification of the chip (more complexity = more time = slower time-to-market), and although slower clock speeds don't necessarily mean less performance, it still has great marketing value. From a technical perspective, I think AMD's model-number scheme makes more sense since it removes some of the impact of the clock-speed = performance misconception, but from a marketing perspective, I think Intel's got it right in making chips with insane clock speeds (3GHz = 333 *pico*second clock cycle, and that's not even counting the ALUs that run at twice the nominal frequency - that just *sounds* impressive, which is the type of stuff that helps to sell these things to the less cluefull consumer or manager).
On an unrelated note, the "Opteron" has to be one of the better chip names so far. It just sounds like it could be the name of some bad-ass decepticon. ("AMD announces its new flagship processor Megatron.")
Some Rudeboy wrote: The only problem might be the cost (it's never cheap)
That's not necessarily true. If you're going just for a MS, sure, you'll pay at least a limb or two. If you're going for a PhD, you'll pretty much be covered (not just in CS, but in most of the sciences). "Covered" usually includes full tuition, plus some living stipend. I'm in a CS PhD program, and I get about $13k for the academic year (+tuition and medical coverage), and during the summer I get about twice the rate of the normal year if I'm on a research grant, and of course you can make plenty more interning for the summer (did that the previous summer and made just shy of twice as much in those three months than what I made in the other nine). Sure, you're not living the bling-bling lifestyle, but it's not bad so long as you don't have to support a family or have large outstanding gambling debts to pay off.
As far as the work goes, I think it depends on a whole lot of variables: the institution, your interests, the professors, how well you get along with your advisor and others in your group, what kind of project(s) the group is working on, how heavy your teaching load going to be, what life outside the department is like (if you don't enjoy your life, it makes it harder to enjoy your work as well), etc. Another poster mentioned something about professors who shun the "real" world and aren't interested in applying the science to actual applications or keeping up with the latest developments. Sure, plenty of those exist. But there are also plenty who are indeed interested in such things. It depends on their interests. Remember that programming in and of itself is just a tool and not "computer science". (Insert prolonged debate about what computer "science" really is at this point...) It's up to the prospective PhD student to find a program that's a good match for him/her. If you just choose some university based on their reputation or the size of the stipend, you may very well end up in an unhappy situation. If you're going to spend the next 4-6 years doing research in CS (or any other field for that matter), do a few hours of research ahead of time to find out all you can about your options and then make an informed decision!
And of course graduate school isn't for everybody.
Skating of various sorts is great exercise for the lower back. I rollerblade and play ice hockey, and I don't seem to have any problems with sitting in front of the computer for about 10-14 hours a day.
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Part of the problem is that the marketing company's lite-brite boxes were unprofessionally made. There are wires and batteries hanging out the side; it has that look and feel of "bombs" you see in movies (like the ones with the stupid "I'll let you know when I'm going to blow up" 7-segment LED display countdown)... and if bombs look like that in movies, then they *must* look like that in real life, right? If they had just made their little LED boxes to have the same size, shape, color, etc. of the other normal traffic signs/signals, that is do a professional job, then at worst people would have just thought that someone had hacked an existing sign (it's not like most people can precisely remember the exact number of signs/signals at every bridge, overpass, etc. they drive past on the way to work).
/.; I should perhaps have said average or typical middle schoolers).
Those signs totally look like some crap that some middle schoolers would throw together at the last minute for a "science" project (no offense intended to you middle schoolers out there who read
Ditto the first responder. ISA-goop matters not very much. Modern x86 processors (Intel or AMD) translate the x86 goop into relatively clean RISC-like operations. From that point of the processor and onward, the encoding/decoding warts of x86 don't matter. Almost any half-way sane ISA (and that's a generous "half-way" as it includes x86) can be decomposed into RISC-like operations. Several years ago when anybody cared about Itanium, Intel even had a paper published in an ACM/IEEE conference on how to implement a really aggressive out-of-order Itanium processor that basically decomposed the EPIC/VLIW insts into a bunch of micro-ops (brekelbaum et al., ACM/IEEE Intl. Symp. on Microarchitecture, 2002).
The cost at the end of the day is a little extra logic (not trivial, but not worth abandoning backwards binary compatibility over) which means some power and area overhead. Not a big deal.
The console makers don't always lose money on the hardware. Typically, they lose money on the first few batches, and then as manufacturing gets cheaper they eventually break even and then even start to make money. The original XBOX was not able to really capitalize on this because MSFT did not own a lot of the intellectual property in the hardware. That's one of the big differences with the 360: they own the IP for the triple-core PPC processor (even though IBM's fabbing it for them), which means improvements in semiconductor manufacturing (Moore's Law) --> reduced hardware costs --> profit on the hardware in addition to licensing fees on software.
The amount of money that MSFT makes on xbox games is also not nearly as much as you might think. The $50 you pay gets divided many ways from the brick-and-mortar stores all the way back through the supply chain to the developer and back to MSFT themselves. If they got $5 per game (which is probably too high), their 11 million units of Halos 1 and 2 would only pocket them $55M (the 11M units figure is about a year old now, and also includes the PC version).
The inquirer speculations are indeed useless, because they'll post fifteen articles on fifteen different possible outcomes. Then after the fact, they'll point to the one article that got lucky and say "See? We told you so!" without bringing any attention to the other 14 that were totally off the mark.
It's like someone buying every combination of lotto numbers and then saying, "Look! I always win!"
I was just in Germany last week, and I saw that they sold gas with an extra 4/10th of a cent per liter instead of the usual 9/10th. I totally didn't understand why they didn't bother with just going with 9/10th.
The difference is that in the tri-state area, it's more of a capacity problem. If there was some optimal way for people to drive (in terms of aggressiveness, politeness, lane changing decisions, speed, etc.), I would expect that it wouldn't make too much of a difference to the traffic problems. In Seattle, a large portion of the congestion is not due to road-capacity issues, but due to driver behavior.
Driving in the NYC area, if I hit bad traffic, I just shrug my shoulders, find a good radio station, and accept the situation. It's far more frustrating in Seattle because it doesn't have to be the way it is!
I lived in CT for a while, and would drive down to NYC on weekends (often on friday nights when traffic is pretty bad), but if you learn the routes, stay away from the GW bridge, have an ez-pass ready to go, listen to WCBS/880 for the traffic reports, and didn't get to NYC at 5-6pm, it usually wasn't too bad. Otherwise I'd take a Metro North train into GCT and subway it from there.
The other difference is that in NYC, you have Metro North, the NJ Transit trains (and buses), the PATH, and the MBTA. At least if your starting and destination points were reasonably close to an appropriate station, you could choose to take public transit. The public transit in Seattle is really weak (basically your options are buses or buses). So for the most part, everyone ends up driving.
The way I see it is that in NY/NYC, the roads/drivers are more like fully-associative caches. You can get mapped to any cache line, and increasing capacity has direct benefits. In Seattle, the roads are more like direct mapped (or at most *very*-lowly set associative) caches where drivers are always fighting for the same couple of cache lines. Increasing the capacity has limited benefits in this case.
OTOH, if the drivers didn't drive slowly in the left lanes, then this crazy aggressive driver wouldn't have to tailgate, switch lanes, cut people off, etc. The "me first" philosophy can have bad impacts on traffic, but that's a smaller problem when compared to the "who me?" drivers out there that don't even realize they're causing a problem in the first place. There are those drivers who tail gate, flash their brights, and honk at you to move over when you're driving slowly in the left lane, and I applaud their aggressive behavior. NY drivers are a bunch of aggressive, crazy, tail-gating, horn honking, assholes, but I would so rather drive with them and be an asshole with the rest of the assholes, than to drive with all of the appendixes** here in Seattle because the NY way is so much more efficient (banning non-hands-free cell phones in Seattle (like in NY) would also be a blessing). I'm not condoning road rage, but don't confuse aggressive driving with road rage.
** I chose the appendix because it's a useless organ. You might not like the anal sphincter because it's smelly and expels feces and flatulence, but it does serve a vital purpose.
Don't know why the parent post was moderated down, but...
it's totally true. I've driven for many years in the northeast, and generally people follow this rule. Living here in Seattle, it's very frustrating to drive because there are often really bad traffic jams at non-peak hours where roadway capacity is not the issue. On an n-lane highway, you only need n morons who drive at the same speed next to each other to make a mess out of traffic (and it happens all of the time). Not even considering the time and cost, adding additional lanes is an ineffective and poorly scalable solution in Seattle without first changing the behavior of the drivers.
The other problem is the fact that there are a lot of oblivious drivers who just don't pay attention. I live downtown near the marketplace, and I've seen plenty of day dreaming drivers casually fly through red lights without slowing down**, and even the occasional idiot driving the wrong way up a one-way street. Such driving skills (or lack of) do not translate very well to the highways. Add to this plenty of other problems such as people who can't merge onto a freeway and then *stop* at the end of the on-ramp, thus making it impossible for anyone behind them to merge either (and part of this is people who happen to be in the right lane not slowing-down/speeding-up to make room for the would-be merger).
As another poster mentioned, moving over is in fact the law. I think if the cops simply started ticketing people for slowing down traffic when driving in the left lanes, a good amount (obviously not all) of the traffic problems in the Seattle area would be taken care of (and it also provides more money in the form of ticket fines, and reduces pollution due to better fuel efficiency, blah blah...).
Another odd phenomenon is that besides the HOV lanes being underutilized, so is the rightmost lane! I guess everyone thinks the right lane is only for "slow" drivers, and of course everyone thinks "*I*'m not a slow driver", and so the second they get on the freeway, they hop over a lane regardless of the traffic conditions. This immediately results in all n-lane freeways having an effective bandwidth of an (n-1)-lane freeway. For those of us who pay some attention and have even the remotest capability to perform dynamic routing, the rightmost lane is (sadly) frequently the fastest way to go.
I just got back from a trip to Germany where I drove on the autobahn for the first time, and the reason everyone can drive so fast (besides it being legal to do so) is that everyone does in fact "stay to the right except to pass". On an unrelated note, if you ever rent a car in Germany and like to drive fast, pay the extra of couple bucks (I mean Euros) to upgrade to something with some juice in it. The VW Lupo I got was gasping at 160km/h (100mph), and there were plenty of cars just *blasting* past us.
** and I don't get it why people tell me I shouldn't jaywalk in Seattle when you've got to be watching for clueless drivers regardless of the traffic signals. Jaywalking is like cars making a turn on red. You don't have the right of way, but if the coast is clear, then proceed with caution. Sorry, just a rant from someone who lived in Manhattan for four years where people would even go as far as doing multi-phasic jaywalking: when the coast is clear in one direction of traffic, proceed to the double yellow line; proceed to other side of street when the other direction of traffic is clear. I've seen a dozen or more people standing along the double yellow line on third avenue (downtown where it's two-way) with traffic zipping around them on both sides, waiting for the "2nd-phase" of the jaywalk. It all comes down to the same thing. You've got to be paying attention.
I (physics undergrad) use a biro and a pad of budget paper for notetaking.
speaking of budget, I used to just take stacks of printer paper (often reams just sitting around the printers in computing clusters) to class and write on that. Add a 3-hole punch and a 3-ring binder, and you're set. If you're worried about the "stealing" aspect of looting the computer paper, I know others who would just take paper from the paper recycling bins next to the printers.
I prefer Extra Fine blue Pilot rolling ball pens, although they will occasionally pee ink on your fingers.
I haven't tried taking notes in class on a laptop, although I bet the constant clacking of someone typing would bug me after awhile.
It will depend on your studying/learning style, but for me, taking a digital picture of the black/white board doesn't work in actually learning the material. I learn much more efficiently by actually copying stuff down on paper since the trip from eyes to hand forces the information to visit the brain at least once. The other advantage is that taking notes (or doing anything quasi-active) helps in keeping you from nodding off after pulling one or two all-nighters. (I had a friend who took a very different approach: he drank a lot of water before class and having to go to the bathroom really badly would keep him wide-awake.)
Others may prefer to just sit and listen to what the prof has to say and rely on the class notes and/or textbook. This doesn't work for me, but I found it to be very effective to team up with someone who learned this way. You've got all of the notes and when you can't remember what they mean, your partner will be able to interpret them for you. And sometimes your partner will need your notes to jog their memory to recall what was taught in class.
This strategy was actually *necessary* with one of my college profs because he wrote so fast (chalk was literally exploding against the blackboard) that you had to write as quickly as possible to transcribe everything from the board to paper. You were writing so quickly that you didn't have the time to digest any of it, so you needed someone else who was actually paying attention to the content to tell you what all those little greek letters and e^-jwt's meant. And for this class, a laptop would have been useless as I don't think I know anybody who can type in boardfuls of matrices, fourier-transforms and equations for chebyshev filters that quickly. Maybe a PDA would've worked in this context, but I haven't tried so I can't say.
The one we used was:
Kids Playing Chicken On Freeways Get Squashed
or in haiku form:
Kindergarteners
Playing Chicken On Freeways:
Guaranteed Slaughter!
(``Kindergarteners'' is an acceptable variant of ``Kindergartners'' according to Merriam-Webster.)
Actually, it doesn't matter that much whether you can get from the `zero' state to the `two' state with or without going through the `one' state first. Even in current processors, interference (inductive coupling), ground bounce, and other effects may cause what should be a `zero' to bounce up into the voltage range that would make it a `one'. That's one reason why the processor uses a clock. It doesn't matter what states the signal goes through so long as it has settled down to the correct voltage by the time the clock ticks and you sample the voltage (well, less the setup time of the latch...).
As mentioned by a comment a few posts down, they used to use base ten in machines (BCD = binary coded decimal), where each base-10 digit was encoded with a 4-bit binary value. Besides the increased complexity of base-10 arithmetic circuits, since each digit uses four bits, there's 6 possible states that aren't utilized. So for example, with two BCD digits, you can represent from 0-99 in BCD, but if you used those same eight bits in binary, you could represent 0-255. I think that's what people may be talking about when they say binary is more "efficient" than BCD. Otherwise from an information theoretic perspective, I don't think one unit is any better than the other (it would be like saying using "kilograms" is more efficient than "grams" or "milligrams" or even "slugs").
IBM didn't do it first. I lived in Manhattan from 1994-1998, and I saw spray painted ads on the sidewalks back then (and it was certainly *not* chalk!). That's not to mention all of the other crazy stuff that people paint on the sidewalks. (I don't know if it's there anymore, but there used to be painted footsteps that went on for blocks in the east village, and then a few weeks or months later, someone painted tools (yeah, like hammers and wrenches) along side the footsteps.) I think the first ad I ever saw painted on a NY sidewalk was from a sneaker company or shoe store, but it definitely wasn't nike.
Reminds me of the SNL skit with Guiliani which was a fake commercial about his new crack down on graffiti. If they saw your tag on a wall or somewhere, a special police anti-graffiti division would spray paint the word "sucks" under your tag. (and for multiple-time offenders, they'd have a special police artist paint "sucks" in the same exact style as your tag.) It'd be funny if someone painted or even just sharpie'd "sucks" onto all of the butterflies.
In "Introduction to Algorithms, v1" (CLR), I recall a little snippet where they mention that 10^80 is approximately the number of particles in the known universe. It's a pretty big number.
For the more technically inclined:
t ye ffective.html
Jim Smith and Guri Sohi have a pretty good overview of how superscalar processors work. You can pull a cached version off of citeseer at:
http://citeseer.nj.nec.com/35243.html
If you want to get a better feel for the complexity (at the transistor-and-wire level), you could try:
http://citeseer.nj.nec.com/palacharla98complexi
This paper is pretty technical, but you don't really need to understand all of the equations to get the gist of it. They're also a few years old now, but still relevant. If you understand how the circuits are organized, and that complex circuits and long wires are expensive (in terms of slowing down the clock cycle), then you can get a decent feel for how complex the proposed register virtualization might be to implement in hardware.
Other posters have commented on how clock speed is not the bottleneck, but it's actually the caches, buses, memory bandwidth, memory latency, etc. This really depends on the application and what you're doing. BUT, just because X isn't the bottleneck, it doesn't mean you have free license to tinker (i.e. slow down) X by a huge amount. Adding a slight bit of extra delay to X can easily make X into the new bottleneck. Removing bottlenecks is really difficult because as soon as you remove one, five other things are now the bottleneck, and you can't get any (or much) further improvement until you remove *all* of them. (The team only goes as fast as the slowest member, a chain is only as strong as its weakest link, yadda yadda yadda...)
And then there's a myriad of other issues such as design complexity, added complexity in test and verification of the chip (more complexity = more time = slower time-to-market), and although slower clock speeds don't necessarily mean less performance, it still has great marketing value. From a technical perspective, I think AMD's model-number scheme makes more sense since it removes some of the impact of the clock-speed = performance misconception, but from a marketing perspective, I think Intel's got it right in making chips with insane clock speeds (3GHz = 333 *pico*second clock cycle, and that's not even counting the ALUs that run at twice the nominal frequency - that just *sounds* impressive, which is the type of stuff that helps to sell these things to the less cluefull consumer or manager).
On an unrelated note, the "Opteron" has to be one of the better chip names so far. It just sounds like it could be the name of some bad-ass decepticon. ("AMD announces its new flagship processor Megatron.")
The only problem might be the cost (it's never cheap)
That's not necessarily true. If you're going just for a MS, sure, you'll pay at least a limb or two. If you're going for a PhD, you'll pretty much be covered (not just in CS, but in most of the sciences). "Covered" usually includes full tuition, plus some living stipend. I'm in a CS PhD program, and I get about $13k for the academic year (+tuition and medical coverage), and during the summer I get about twice the rate of the normal year if I'm on a research grant, and of course you can make plenty more interning for the summer (did that the previous summer and made just shy of twice as much in those three months than what I made in the other nine). Sure, you're not living the bling-bling lifestyle, but it's not bad so long as you don't have to support a family or have large outstanding gambling debts to pay off.
As far as the work goes, I think it depends on a whole lot of variables: the institution, your interests, the professors, how well you get along with your advisor and others in your group, what kind of project(s) the group is working on, how heavy your teaching load going to be, what life outside the department is like (if you don't enjoy your life, it makes it harder to enjoy your work as well), etc. Another poster mentioned something about professors who shun the "real" world and aren't interested in applying the science to actual applications or keeping up with the latest developments. Sure, plenty of those exist. But there are also plenty who are indeed interested in such things. It depends on their interests. Remember that programming in and of itself is just a tool and not "computer science". (Insert prolonged debate about what computer "science" really is at this point...) It's up to the prospective PhD student to find a program that's a good match for him/her. If you just choose some university based on their reputation or the size of the stipend, you may very well end up in an unhappy situation. If you're going to spend the next 4-6 years doing research in CS (or any other field for that matter), do a few hours of research ahead of time to find out all you can about your options and then make an informed decision!
And of course graduate school isn't for everybody.
Skating of various sorts is great exercise for the lower back. I rollerblade and play ice hockey, and I don't seem to have any problems with sitting in front of the computer for about 10-14 hours a day.
Do it for the children (if not for yourself).