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For the Javascript part, you would need a programmable function block. One option would be not to support Javascript (OK in certain parts of the world). You cou
by khitchdee 14y ago
For the Javascript part, you would need a programmable function block. One option would be not to support Javascript (OK in certain parts of the world). You could organize your chip so that there are several fixed function blocks for things like image decoding, video decoding, text rendering and graphic composition coupled with a programmable function block for the Javascript. The point here being instead of doing all your computation through a program, do only as much as you absolutely have to. The parts that you can hardcode, hardcode to make you chip more green. Web browsing has been given as an example because its a commonly used function and on its own it can justify building a gadget like the Chromebook. So, if you have a narrow function that the gadget is going to be used for, you're better of going full custom than programmable function. I'm doing a more complete analysis of what it would take to build such a chip. I'll publish it when its ready.
- icebraining 14y agoOne option would be not to support Javascript (OK in certain parts of the world) Where? So, if you have a narrow function that the gadget is going to be used for, you're better of going full custom than programmable function. How much inefficiency per unit in building small batches of a custom chip, as opposed to many units of a single design, would it take to overcome whatever gains you got when running the device?
- khitchdee 14y agoIf you could identify a large population of users that could be serviced with a narrow usage scenario and they agreed to stick with their function for say a year, you could build a viable solution the fixed-function way. For example, in India, PC penetration is only a few percent. Most of the population is completely technology agnostic. If you could identify the top three uses for a computing gadget for say the farmers of India, you could build a fixed function chip at low enough cost and high enough volume for them which would give them some solution instead of no solution because PCs are too expensive or consume too much power. Users such as these would probably not ask to change their gadget for years.
- icebraining 14y agoYou can get an ARM system with a 700Mhz CPU, 256MB of RAM, an HD capable GPU and USB support that runs off a 300mA power supply for $25. How low could you realistically get with a custom chip?
- khitchdee 14y agoMuch lower
- npsimons 14y agoAnd what evidence do you have for this? We aren't talking about off-the-shelf, pennies per chip PICs here. These things would not only have to recoup the design costs (not cheap for this level of complexity), they would be expensive due to the previously mentioned huge caches (basically RAM on chip) and the fact that you really aren't going to get by with web browsing without something Turing complete.
- khitchdee 14y agoFor the application that I have in mind which is low cost computing alternatives for India's tech isolated millions, I think we could get by with a 320x240 resolution screen which means each frame would be pretty small and we should be able to get by with 2 frames of total buffering. At 6 gates per bit, assuming a 16 bit color depth, that would be 6 x 16 x 2 x 320 x 240 which is about 15 million gates. Assuming the rest of the chip is much smaller, and assuming we fabricate on 180 nm process means chip area is about 15million x 0.18 x .18 x 10(-6) mm squared or .5 mm sq. That's a pretty small chip. The only cost we would have to control is the design cost. Over time we could figure out how to do this with say a product line.
- markbernard 14y agoSo when the next new web tech comes out you just obsoleted the chip and have to throw them all out. When a new image format arrives or video codec or version of HTML all those chips are trash. Yeah that's green.
- khitchdee 14y agoYou would refresh your technology at some rate say once a year and try to match it with rate of the other technology suppliers just like in the microprocessor case. Your cadence is a little shorter.
- bonzoesc 14y agoMy iPad from over two years ago browses the web with the same capabilities as the iPad 4, just a bit slower and lower-resolution. That I should have to throw it away and buy a new one because the web changes is the antithesis of "green." General purpose computer hardware is an investment in a toxic industry to enable the cheap and clean process of disposable software.
- khitchdee 14y agoYet we keep upgrading our hardware
- npsimons 14y agoMaybe you do. Some of us who are well beyond "power user" are still operating on hardware from many years ago. It's all about picking (or making) software that doesn't suck.
- khitchdee 14y agoThe longer you stick with your hardware the greener the process gets. Still, software has spoilt us for choice and I agree few people write software that lasts.
- jarel 14y agoWhile I don't agree with everything you say(+), I'd like to thank you for taking the time for writing all this (your initial post and your comments in this thread) up. Definitely one of the more interesting reads on HN today. (+) Web browsing is extremely complex: We have video, audio, js, plugins (flash, java, silverlight), changing standards for html, css etc. Because of this, it's not very well suited for custom chips. For this reason, modern smartphones contain both custom chips for the "phone" functionaltiy and a flexible microprocessor for Angry Birds. There might be other areas where a few custom chips might save a lot of resources in the long run, though.
- jholman 14y agoThe Chromebook is only a reasonable appliance precisely because of the sophisticated programmability of Javascript. So your "one option would be not to support JS" proposal is directly contradictory with your selected example (the Chromebook) of a single-function computing gadget. More generally, I'll echo the concerns of everyone else here: we seem to be getting greener by using more-general-purpose computing, that necessitates less devices, and less frequent upgrading. Especially because we now see that once devices reach a certain level of power, we actually buy new ones far less often. (Many people now happily own 5-year-old desktops, not because they cannot afford more, but because they're too LAZY to buy a new one for the small marginal benefits... and laptops are headed slowly in that direction. Cell phones and tablets are still far from that transition.) On the other hand... your observation about the 3% penetration in India, assuming it's factually true, does sound like SOME kind of an opportunity. Making things radically cheaper is always an important disruption (c.f. the original sense of "disruptive innovation", which doesn't just mean "we beat the competition"). And certainly if you can sell to 0.01% of Indian farmers (say 100k households?), that's a hell of a lot of units over which to amortize the high fixed cost of circuit design and tape-out. Although only if you really can come up with a single design that meets the needs of such a huge and probably diverse market. Sounds very hard. Plus, of course, as many sages (e.g. pg) observe repeatedly, if it were obviously a good idea then your competition would already have done it, which means that IF it's ACTUALLY a good idea, the crowd of naysayers here (myself included) is a good sign for your project. ;) In short, I'm really sceptical about your fundamental hypothesis, but good luck with figuring it out.
- khitchdee 14y agoYour words are encouraging and discouraging at the same time. Nice post. 10 million PCs sell yearly in India in a population of 1 billion.