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Comment by simias | Hacker News Reader

That's a very good point. An other comment points out that the computation has to be tied to previous blocks to maintain integrity but it would be great if once the hardware is decommissioned (newer hardware came out/bitcoin crashed) it could be repurposed to do something else.

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Well, the GPUs and FPGAs are (and have been) easily reconfigured after decommission. ASICs, however, are inherently specific-use (Application-Specific Integrated Circuit). So because of the requirements of the Bitcoin computation mentioned in my comment [0], repurposing of ASICs is not possible.

0. https://news.ycombinator.com/item?id=6796189

Of course, with bitcoin it's not possible (unless you want to crack sha-256 hashed passwords maybe?), I was wondering if by designing the bitcoin algorithm differently that might have been possible.

For instance, to stay with the protein folding example, maybe bitcoin could have used an algorithm that used similar logic as the one used by the folding@home project but with different input data and expected results. Once the hardware is no longer needed for mining it can be easily repurposed for research.

> unless you want to crack sha-256 hashed passwords maybe?

It makes you wonder if we'll ever hear of anyone turning their bitcoin cluster to this purpose. Perhaps someone unauthorized.

Edit: Downthread, nwh explained why this isn't possible:

> No, they can't crack passwords. They increment a nonce at the end of a supplied string and only return if the nonce results in a low hash. They're not a generic "fast SHA" device like you're thinking.

well, btc mining involves sha256(sha256(x)). Not being a hardware person, I don't know if the designs of the asic miners can be re-used to just compute sha256. Maybe, maybe not?

Very specific sha optimizations are put into these circuits, which makes it doubtful that they can be reused for any other kind orf computation involving sha.

To do that the chip would have to be designed to have that feature already. Otherwise it's like looking at a bicycle and wishing you could repurpose it into being a plane. The structure is just not there to do that sort of modification.

Hopefully they can recycle the raw materials, and can build upon the designs.

Eh, not really. I don't think any form of electronics is recyclable, best you probably get is third world countries burning the boards to get the gold out and killing themselves with the gases produced.

I said (and stressed) "hopefully" - I understand it's not mostly the case presently.

The raw material is worthless. It's the processing that is expensive.

Well some of it can be recycled, like rare metals, but you are right that the majority of the value is in the combination of those raw materials, rather than the materials themselves.

And of course as technology advances, both actual composition and what can and cannot be usefully recycled will change.

Yes, but how many general purpose chips have been made that aren't useful for anything any more - 386, Pentium, etc. After their useful life has ended they just end up on the scrap heap anyway.

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