When I was peripherally working on some HPC stuff, there was a comment by one of the hardware guys that it mattered which national lab you were building the supercomputer for, because the guys at high altitude like Los Alamos get a lot more bitflips than someone closer to sea-level like Argonne. Although that said, for an exascale supercomputer, the mean time between uncorrected bit flip somewhere in the machine is on the order of a few hours, which means that large supercomputer-scale workloads should actually expect to hit a bit flip in their computation.
Cosmic rays can probably be resolved with some parity bits and redundancy. Especially since these don't have to be located way up in geosynch, lower orbits get you more magnetosphere protection.
Not that it isn't a problem, but I think heat dissipation will have the edge.
I worked at the architecture level on designs to mitigate signal corruption inside the asic. I don't remember the exact numbers, and obviously it depends on the design. but you need to add error detection and correction on every path (busses, mixes, registers, function units, etc). the number I seem to recall was a 25% area overhead and a nominal decrease in clock rate. this was for an earth-bound very large machine, so idk if that would be sufficient for space. usually those designs have much larger nodes and much slower clock rates. primarily because of damage caused by ionizing radiation that accumulates over time.
so sure, the heat issue seems fatal, but rad-hard designs will certainly have a bottom line impact
Nope, if it's one person, it's gotta be Szabo. Only person in the world who wouldn't cite his work would be himself. (If it's more than one person, of course it could include Len.)
I don't believe Hal was Satoshi (there's no evidence to suggest it), but Bitcoin never would have succeeded without Hal. He deserves as much credit as Satoshi.
I believe this means that the part's computer has the vehicle's VIN loaded into it with a computer that can only be purchased/used by a certified technician. If he was to buy a new part, it would have a blank VIN; and if he pulled one from a junker, it would have that car's VIN.
(edit: should also say, I think a VIN mismatch would cause the ECU to refuse to work with that part and shut down)
It gets even more fiendish than that - you can have entire linked dependencies of locked modules. My old Saab’s key was locked to the security computer, to the column immobilizer, then to the engine computer.
Lost one key? Bummer. Lost all your keys? $2500, several hours of reprogramming time at the dealer, and a bunch of new parts shipped over from Trollhattan.
Thankfully the hacking scene has managed to bypass lots of this as Saab no longer exists to make parts. But this was the state of the art in 2003. I’m sure it’s even worse now.
It's going to get worse - on most cars the CAN bus is not encrypted and the messages are not signed. There was a comment here recently where a tech in the auto industry claimed that one manufacturer was planning to start signing the CAN bus packets. That will mean it likely becomes impossible to do things like re-code the PCM for a motor with a different VIN so you can re-use the PCM in another vehicle.
I wonder if this didnt start with 2005 7 series when it received FLIR Night Vision system. That thing was locked down due to ITAR and gave BMW excuse to pair with ECU.
Don't the salaries at AppAmaGooBookSoft (sorry, patio11's spelling is canonical here) themselves include a risk premium that is incenting the people there to stay instead of going to work at a small company with the opportunity to topple one of them?
How do you model those risk premiums against each other? It seems like they should both go infinity in order to keep anyone from ever leaving anywhere.
It's a market for risk. Risk premiums are worth what tech companies will pay for them. If it's more expensive to find a replacement than pay a risk premium, tech companies should and will pay the risk premium.
In the long run, the price of the risk premium = the cost of replacing the employee.
I love the suggestion of ripping out the concrete and selling bits of it as souvenirs to fund the pouring of fresh concrete. I'd personally extend it into a monthly farming operation.
LOL, I swear it feels like the answer to every "why is this weird computer thing this way?" question I see is "because we used to do it this way on punch cards."
Wait until you find out that "coder" originally meant "someone who encodes messages into Morse". And if you start digging into the word "code", you'll find it comes from latin "codex" which is a mutation of "caudex" meaning, literally, "tree trunk".
Because back then, people would write on wooden tablets covered with wax.
So.. next time you see a kludge and think of "historical reasons", consider that "historical" goes back much farther than 20th century. :)
And, what did the word "computer" mean back in the day? Hint: they were mostly women. And, they defeated the Nazis in World War Two, with the help of Alan Turing and his crew.
