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Its a good article but the author missed the third reason hardware can be vastly cheaper, which is lack of abstraction. You can use google search to add 0x9 +
by VLM 8y ago
Its a good article but the author missed the third reason hardware can be vastly cheaper, which is lack of abstraction.
You can use google search to add 0x9 + 0x2 and get hexadecimal 0xb... however that involves dozens of layers of abstraction and endless formatting and parsing that are fundamentally useless in the long run for something like a GPU display.
The 4th reason hardware is vastly cheaper is it needs less testing.
In the example above you can either trust your FPGA/ASIC software to implement a byte-wide full adder properly, because thats kinda a basic task for that technology, or you can whack the byte-wide adder with all possible test cases in a couple ns on real hardware, all possible binary inputs and outputs are quite well known and trivial. When you ask google, or worse, alexa, to add two hexadecimal digits there are uncountable number of theoretical buffer overflows and MITM attacks possible spyware/virus infections and similar such nonsense at multiple layers you probably are not even aware of.
The 5th reason hardware is vastly cheaper is environmentalism and energy costs. I have trouble estimating the energy cost of a byte-wide adder in a ASIC or a CPU, surely it can't be more than charging and discharging a couple sub-pF capacitors... takes billions of transistors switching like crazy to dump the 100 watts a server motherboard can dump and a full adder doesn't take many transistors. On the other hand the infrastructure and environmental damage required to ask Alexa to add two hex digits is very high. You can piggy back on it by passing the buck; well, we need that environmental damage and economic cost to enable netflix at which point asking alexa questions is a drop in the bucket, but people have polluted for centuries on the same argument (well, its just a little extra lost plutonium and compared to above ground nuclear testing its a drop in the bucket, etc)
- blattimwind 8y ago> The 4th reason hardware is vastly cheaper is it needs less testing. This goes against all experience I had with hardware, and everything I have ever heard from every single embedded/electronics engineer.
- badpun 8y agoIt may be because, outside of a few domains, we just accept software failing all the time, and hence do little testing of it.
- taeric 8y agoI think the implication was that there is less testing needed from the software side. That said, I suspect it is also a bit misleading. If you are relying on functionality of the hardware for esoteric things, you test them heavily.
- pjc50 8y agoIt moves the testing around: you don't have to test it yourself, because a huge amount of effort went into that before starting to cut IC masks and each unit is individually tested off the production line.
- ddingus 8y agoGotta test the shit out of hardware features. True. At the application level, less is needed. Spec will be met.
- VLM 8y agoTesting every possible failure mode of a simple full byte wide adder is in fact pretty non-trivial and hard work. Troubleshooting everything that could theoretically go wrong when asking Alexa to add two numbers is simply impossible or incredibly expensive. Space shuttle computers for autolanding are possible although testing suites are expensive, as you state. Implementing that process to the same level of reliability using a vast distributed software technology like Alexa would be essentially an infinite cost. Its a given level of reliability problem; can't compare the apples to oranges of extremely unreliable software or even worse, networked, solutions to something as relatively cheaply reliable as hardware.
- int0x80 8y agoI don't think it misses abstraction. It is covered under specialization costs.
- acpetrov 8y agoThe Alexa bit really shows that processing speed or "cheapness" doesn't always matter. The VM in AWS that eventually does that hex addition could have done 10^N more of those same additions in the time it takes Alexa to hear the question and respond. But, humans are big and laggy, and I don't know if I could type in the question to Google or even a terminal faster than getting the answer from Alexa.