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On Thu, 6 Jan 2000, David Schwartz wrote: > > > > You are making his point, not refuting it. All these > > > things have moved to > > > 32-bits where they would previously have been done with 8-bit > > > or 16-bit > > > processors. They will likewise move to 64-bits. > > > > > > > you are missing the point. > > No, you are missing my point. > > > as stated before: embedded systems use the smallest, most efficient, most > > inexpensive chip that is up to the job. > > I realize that this is common sense, but it's just not true. The defintion > of "the job" is depedent upon what chips are available. When the scope of > the embedded system is defined, it's based upon the current level of > technology. > > Why did the Hubble, and embedded system, just get upgraded to a 486-50? > Obviously the system that was there before did the job, right? > > No, what happened was the availability of more powerful embedded processors > changed the _scope_ of what the job was. This is what has _always_ happened. > > And the amazing thing is that the fast chip will be less expensive. The > reason is simple -- the only significant difference in price between a chip > one generation back and a chip three generations back would be due to a > difference in pin count. And the chip one generation back will be suitable > for more tasks than the one three generations back. This higher volume will > often result in _lower_ cost. > > In fact, it's hard to find non-specialized '286s in wide distribution now. > This is for an obvious reason -- it doesn't cost that much more to make a > '486, and the potential market is larger. > > > 8bit chips are still used all over the place. And even in 38 years time, > > there will be plenty of tasks that can be done with a 32bit chip and a > > lightweight unix-like OS. > > Yes, but you will find that they won't be. > > > Why would you use a 64 bit chip if a 32bit would do the job? > > > > The 64 bit chip is bigger, so your device has to be bigger. > > Why is that? The 64-bit chip can have an 8-bit external bus. And the 64-bit > will be made with leading edge technology, producing smaller dies. > > > It will need a lot more power, so your device has to be bigger, needs more > > expensive batteries, needs (a larger quantity of) and/or (more expensive) > > ancillary components.. etc.. > > Not so. The 64-bit chip can run with a lower clock rate and still get the > same amount of work done, reducing EMI. Why will it need more or more > exensive ancillary compents? No law says the external bus implementation has > to be 64-bits. > > > And finally, the 64 bit chip will itself cost a lot more than the 32 bit > > one. > > Bull. The volume of the 64-bit chip will be much higher since it can do a > larger range of tasks. This volume increase may actually result in the > 64-bit chip being cheaper. > > > It's extra cost on top of extra cost on top of extra cost. > > I don't believe it. Let me put it this way -- what's the current cost > difference between a '286 desktop and a '486 desktop? One is 16-bit, the > other is 32-bit. It's zero, basically. Why is that? Doesn't the '486 need a > more expensive bus architecture? Doesn't it need a more expensive processor? > > > Granted there will be plenty of uses for 64bit chips in the future, but > > there will also be plenty of tasks suitable for 32bit chips... > > Sure, but those tasks will be done by 64-bit chips even though they're > suitable for 32-bit chips. Everything will. It's the same reason I'm using a > P3-500 to write this email even though a '386 would suffice for the task. We > redefine the tasks to fit the available hardware. > Predicting the hardware environment of 2038 is rather silly. 38 years ago, we were still using magnetic core memory, the few hard disks around had a couple of megabytes at most and cost a couple hundred thousand dollars, COBOL and Fortan were just a few years old. The most powerful computers were .1 MIPS or so. A lot of processing was still done on punch card hardware. Direct projection probably doesn't work because atomic quantum limitations are on the horizon. But the 32/64 distinction will be history long since. john alvord - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/ | ||||||||||||
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