Posts by John Robson

Re: Great idea...

So they have to replace a huge number of buried valves to install the fibre... wouldn't it be easier to ... just run the fibre overhead, or to use a pipe which doesn't have valves...

Re: Suppression of citizens

Nuanced conversation is all well and good, but you can't have nuance around security... it's hard enough to do security well, let alone when trying to ensure that your black paint scatters 99% of incoming light.

There aren't many things that are black and white - but encryption is one of those things:

- Either communications are encrypted at source, and only able to be decrypted at the destination OR

- they are not effectively encrypted, and may as well not be at all

"Of course the biggest saving would be to defund space"

For a very limited use of the word saving.

You could save on your food bills by not eating.

So there is probably $8bn of padding in there?

Re: I can see why

"I don't want some alert on my phone popping up every single time someone with an Apple Watch walks past"

That's not really how it works though - If they are within range of the airtag it won't alert anyone else, since it's clearly not being used for tracking.

"I'm sorry but exposed PSU capacitors in the chassis are a real worry"

Why?

They're only exposed if you dismantle something you're not expected to dismantle. i.e. they're as exposed as the exposed capacitors in any ATX power supply, if you take the case off the power supply you have exposed capacitors...

Re: RAM

Not that I would suggest wikipedia is all knowing, but it's usually a good reference.

An SoC "integrates all or most components" "on a single substrate or microchip".

And looking at the M1:

"RAM is on the M1 system-on-a-chip (SoC). While it’s not located within the processor itself, it’s still part of the same silicon seated to the side of the other fundamental components."

If there ever was a technical definition that included just the north/south bridges being integrated then I think it's lost the dumbing down war that society seems to be waging against itself.

Re: RAM

SoC means whatever the person making it meant it to mean really... in this case the memory is part of the SoC, and that is in no small part responsible for the performance we see.

Re: RAM

"The reason accessing GPU memory over a PCIe bus (which is faster than TB4 though still far slower than the M1 Mac's memory bandwidth, and still quite problematic for latency) isn't a problem for GPGPU because when the CPU needs to access GPU memory it isn't latency sensitive"...

And we've never had multiple levels of cache, memory, disk - tiered storage works for memory as well as archives.

The memory on the M1 is stupid fast, clearly no comparison with anything external - but even DDR4 3200 was only 25GB/s, well under the speed available with TB4.

I'd love to have some idea of the intrinsic latency of TB4, but google just shows conversations about audio interfaces, and the latency is so far below the limits of human audio perception that it's been basically irrelevant for many years now. Memory is certainly not something you'd want to run over many metres of fibre based TB (given that we're adding at least* two nanoseconds per foot), but I expect it to provide a pretty good "next best" when mounted close (basically directly attached).

Again, clearly the onboard memory will have lower latency, but that's not necessarily the only relevant benchmark - and slightly slower, but reusable, memory is something that could reasonably catch on - particularly because we now have an interface that is basically universal. A laptop with some extra memory when docked...

* At least - it depends on the medium, but probably closer to 3 because the speed of light is slower in a fibre than in free space, and the signal gets to go both ways.

Re: Thank god for small favors

"Ah yes, but given the lack of chargers it is highly likely that you may spend as much time queueing as you will charging if you managed to arrive just when all chargers filled up. In other words, you then spend time watching for people trying to jump the queue."

Ah - someone who doesn't have an EV making up situations again. If I arrive somewhere and the chargers are all in use I'll probably carry on to the next charger, at the second one I'll check how long the vehicle in front is likely to be and make a judgement call (based on the state of the bladders in the car), only at the third will I usually wait.

Of course this hasn't happened in a very long while, because it's already pretty rare, and getting consistently rarer with public chargers becoming both more numerous and faster.

And it's only ever something you ever need to think about on relatively rare long journeys - because 98% of the mileage is done without ever touching the public charging network. Whereas an ICE vehicle is always looking at the next fuel station, even when you are only doing typical (and inherently inefficient) short journeys.

Not everyone can charge off road, but the vast majority can (24% of households don't have off street parking, but 23% of households don't have a car - those groups won't perfectly overlap, but I suspect there will be a correlation that is substantially better than random).

I often see queues at dino juice stations, and remember them being common as well. The queues might only take 5-10 minutes but this affects ICE owners for every mile they do, not so for EV owners.

Re: Thank god for small favors

"I think the key question here is how much that costs in terms of energy and range"

Well, actually it costs some energy, and *improves* range - because the batteries spend very little time at the less efficient lower temperatures. Of course if you are plugged in overnight then the batteries can be prewarmed from the mains, so the range is unaffected (though the electricity cost will still exist).

"Personally I prefer a PHEV - best of both worlds."

Or the worst of both worlds, carrying around multiple basically independent power trains...

A modern 350kW charger (in a car that will take it) will give you enough juice to do your next 2 hours of motorway driving in less time than it takes you to relieve yourself of your previous drink (6 minutes provides 35kWh, which is about 140 miles or two hours on the motorway).

It takes easily that long to pump liquid fuel (and pay for it), although you probably need to do it less often, but comfort breaks are a safety thing as well as a comfort thing - and you can't take a break whilst you fill up, because you have to supervise the pump.

Long journey in Australia as an example.

Re: Thank god for small favors

Well - since deisel will be significantly gelled at that temoperature... you might find that even ten miles will beat an ICE.

Or you could look at actual behaviour... Let's pick norway, since they have pretty cold winters. Teslas are well used as well - because they manage their battery temperature.

So it's not inevitable that an EV range suffers any more than an ICE does.

Re: Thank god for small favors

And physics is why decent EVs thermally manage their batteries.

I read it as the common accusation that the heater was to blame... If you drive an ICE vehicle that gets 50mpg you lose about 8 miles an hour of range idling the engine.

In an EV if you assume that you are going to use a 4kW heater constantly (which strikes me as rather unlikely) then you give up ~16 miles an hour.

Yes, in percentage terms it's worse, but I've been very generous to the ICE here. My last ICE vehicle was meant to get 50mpg, I used to get ~35-36 on a good day (worse in the cold) - so that was probably losing 11-12 miles of range an hour.

An EV heater should be a heat pump, and shouldn't need a constant 4kW (being in a small box with four single bar electric heaters seems like it would get quite warm quite fast, so even 4kW heat required seems overkill). If you drop to 2kW heating load you're already down to 8 miles an hour range - if you can lower that load using a heat pump then, hang on I was already losing less range than my ICE vehicle.

Re: Thank god for small favors

You could get a vehicle with a decent heat pump :p

Re: Turbo Pascal - Missing Semi-Colon at line 454

If you know the code is missing a semi colon, and you know exactly where it is missing a semi colon... then just assume one is there...

You accidentally hit the n key...

"Modern tag lie" is presumably what you meant to type

Re: Ah, the old moving goalposts

"AV are not up to human standards"

I think you overestimate the standards of human drivers.

For appropriate roads (and here motorways are pretty much the ideal case) AV can already do two things:

- Navigate the motorway better than a meatsack

- Hand back to a relatively fresh meatsack at the far end

- Thus improving the safety of roads it's not used on

Meh - it depends on *how* they disengage...

It might turn out that it's better to stop than just stop controlling stuff...

Re: "the next evolution in delivery technology"

You only need emergency drugs to be kept cold for the flight though - if it's not needed in the next thirty minutes it's not an emergency delivery.

A relatively small pack of dry ice in an insulated container is likely to be more than is needed.

One of my medications needs to be kept refrigerated, but it is always warmed to room temperature before use (since very cold injections aren't all that fun). I presume the same is the case with insulin (just checked - 28 day lifetime at reasonable temperatures), which would probably mean that you don't even need to actively cool it, maybe wrap it in a little bubble wrap if you live in a very hot part of the world...

Re: "the next evolution in delivery technology"

There are very few places where the roads are not going to be maintained anyway, and the carbon footprint of the person is not tied to their job.

A failure in tracking isn't a reason not to use a delivery - you'll end up with exactly the same problem with any delivery mechanism.

If you *must* have nuggets at 3 in the morning then I question your choices - but I'd suggest that a fleet of drones shouldn't be operating at 3 in the morning anyway. A simple bike is almost certainly the better choice.

If you need an AED at 3 in the morning then absolutely send a drone, or maybe just don't - since you seem to think that the drone would then be responsible for the rest of that person's lifetime carbon emissions (at least you attribute those to the trike).