50% power efficiency is for burning gasoline, not oil. Once accounting for energy spent on refining oil into modern gasoline it is like 35%. And with that it will consume less oil to burn it on modern power plant approaching 50% efficiency even accounting for refinery losses and then use that in EV.
New EV from Renault and Fiat are below 25K Euro in Europe without subsidies. They are still more expensive than similar sized gasoline cars with manual gear shift, but the difference is small and will pays off in few years.
Gasoline is expensive at the moment because of the Iran war. But as soon as it's done the price of gas will fall markedly and people will forget all about EVs.
EV in China with a reasonable range is already cheaper to manufacture and to buy. Inevitable the same will happen in Europe in the next couple of years. Given the massive improvements in charging infrastructure I do not see why EV would be a default option.
Heat pumps are mostly useless when it is minus -20 C. Diesel heater is the most practical solution. Sodium or LMFP batteries will help, but even with them the range reduction in winter due to the need for heating and increased drag from cold air is just too great.
I meant in heat pumps in cars due to size constrains. For homes there are heat pumps that work even at minus -30C, but one just cannot fit that into a car.
And I really do not get why there is no even option to have a diesel heaters in cold climates. It adds like 100 kilometres per long trip for a litre of fuel when it is cold and allows to use smaller and cheaper battery in EV.
you're not making the point you think you are. The average January temperature in most of Norway is about 10 C higher than in most of Yukon and Alaska. Norway just isn't that cold.
That said, heat pumps absolutely do work in -20 C. I would know because i have two at home and one in the car. All three worked just fine at -25 C this past winter.
How many homes have heat pump as their sole heating?
That's a useless statistic without knowing if it's their sole heat source. Just based on costs, I'm betting there's a lot of wood stoves and pellet stoves kicking around.
diesel fuel itself needs to be heated at -20 C and below. I used to have a diesel car which would start itself up periodically when its fuel temp was getting close to -20 C, just to warm up the tank & pipes.
Yeah, the 1999 diesel truck I had did the entirely opposite thing: it had a 120v electric block heater, so you'd plug it in when it was cold. (In New England, I used it once to see how it worked, but never actually needed it in practice.) At the time I saw stories (I never confirmed in any depth though) that Minnesota had 120v outlets on parking meters, giving some sort of weather-encouraged compliance :-)
Ok i get that some people really do need to deal with extreme temperatures regularly, but it totally misses the point when discussing a mass market car like the Corolla. It’s like asking business casual footware to be equipped with crampons for when you need to walk up a glacier.
SeL4 or proof assistant are not panacea. They do not help if assumptions about the task are wrong. And correctly formulating the task in real world is very messy.
So physical security is just as important. I really like how ARINC serial bus on planes work. One can have a reader that is physically incapable of sending anything to the writer. This allows to connect entertainment systems to flight data sensors safely.
In Airbus this system is replaced with Ethernet switches that in software ensures separation of traffic. The software was proven mathematically. But I am skeptical that it is absolutely bulletproof as a client under malicious control can influence Ethernet signaling and may exploit hardware bugs.
> SeL4 or proof assistant are not panacea. They do not help if assumptions about the task are wrong. And correctly formulating the task in real world is very messy.
Nobody said sel4 was a panacea.
My claim is that doing this kind of computer security is possible. It's just expensive and inconvenient. We know how to make computers a lot more secure than they are today. The limiting factor isn't humanity's knowledge. The limit is that barely anyone wants to pay the bill.
> My claim is that doing this kind of computer security is possible.
But your evidence does not support that claim. SeL4 has proven that it is possible to design a secure microkernel and prove its security guarantees. It does not prove that you can build entire systems (filesystem+database+web server+browser) on top of that kernel while maintaining the same security guarantees.
I'm all for improving the state of computer security, and I'd love for capability systems like SeL4 to become more prevalent. But it's only a microkernel, and it's by no means certain that the PeopleSoft vulnerability exploited here required a kernel-level compromise.
I don’t expect every piece of software written to be proven correct like SeL4. But I don’t think we don’t need to do that to get big improvements in the security of a lot of systems. Honestly the biggest insight I take from sel4 is that we can get improvements in security by breaking up a large program into isolated pieces. Give each piece as few permissions as possible, so a compromise of one part doesn’t lead to a whole system compromise. And give them a way to talk. This has big benefits for reliability - since you can fail and restart individual processes. And it has benefits for security, since a system compromise should require an attack of multiple systems simultaneously. And it has benefits for debuggability, since you can add tracing at the comms layer or isolate modules for testing.
Wasm does this. Erlang does this. SeL4 does this. Chrome is built this way. The windows driver model is moving this way. And so on. You want a solid core to build around - which is what SeL4 and beam try to be. Then it’s up to us to use those primitives and build good software. Combine that with a memory safe language (rust, go, c#, etc) to protect against buffer overruns and use after frees. And a picture starts to form of how you can build software that is a lot more secure by default.
I don’t think perfect security is worth the cost for many companies. But so many security leaks happen because of amateur hour somewhere. Bugs happen - I get that. But a single bug in a C++ program shouldn’t immediately lead to RCE with system level privileges. This stuff isn’t rocket science.
You mean something is theoretically possible, but in practice only works at small scale and is otherwise effectively impossible. You only have so many resources for all those big topics.
And after you spent all the world's resources on the "perfect", formally bug-free software, you get hacked via social engineering or malicious insider.
> The limit is that barely anyone wants to pay the bill
Do you even have any experience with how most companies work? SMEs barely have the cashflow to cover their daily expenses, let alone suddenly pay thousands for regular professional security audits and overhauls of their code. This is why security is an afterthought.
If restaurants can't make sure their food is safe to eat, they shouldn't be allowed to be in business.
If builders can't build houses to code, and the buildings fall down, they shouldn't be allowed to stay in business.
If civil engineers build bridges that fail. Or doctors hurt patients. Or police officers shoot innocent people, they shouldn't keep their jobs.
Software engineers are no different. If you collect my user data and it's at high risk of leaking on the dark web, either clean up your act or close shop.
The main issue is that market evolution will always surfaces the most cost-efficient entities within the ecosystem pressures.
That means designing the ecosystem pressures is crucial: things more meaningful than just pure capitalist private-profit logic must by enforced by thoughtful regulation or otherwise the ecosystem converges for private-profit of a small sliver of individuals (billionaires) to the detriment of all other ecosystem members (99% of the world population).
This holds for anything broader than pure private gain, may it be security, social fairness or ecological topics. Sole monetary-value optimization for private gain must be properly constrained or else it results in pure predatory capitalism that implodes society from within, may it be through leaky security, poisoned environments or social unrest.
Yeah this is an interesting argument with respect to why we keep burning carbon. For both software and systems security and rapid climate change, we know the solution. But we haven’t been able to sway the incentives and the system keeps churning out bad results.
Zram also supports a block device for pages that do not compress. So the primary advantage of zswap is that one can use its swap for hibernation while it does not work with zram.
Zram support for a block device is quite misleading, since there are no automatic mechanisms for enabling this. You have to build your own daemon to scan pages and take action on them. Zswap doesn't have that problem.
On x64 CPU for laptops the memory bandwidth is rather limited and a fast compressor like lz4 can saturate it. As the result latest SSD are faster then z-ram when using hardware encryption on SSD.
Swap is so much more than a safety net and can increase performance if used correctly. See Chris Down's "In defense of swap" and follow-up that breaks down zram vs zswap.
Swap is required for hibernation. And with fast ssd or properly tuned zram/zswap one can run task that use 10%-20% more memory than installed RAM. Surely there is a slowdown, but it is not that big especially when SSD can read write more than 5GB/s.
TL;DR that swap shouldn't be seen as "spare RAM", but a mechanism for paging out anonymous pages, which is desirable in many circumstances in avoiding OOM situations and making memory management work better. It paradoxically typically reduces I/O thrashing.
It helps with performance by allowing your system to have more free physical RAM. And by free I mean for caches. It does this by moving data from inactive pages out of physical RAM. You shouldn't care about the peak bandwidth of zram vs. ordinary swap because latency matters more.
I mean, are you saying ‘but more RAM?’ because obviously yes that’s true but not a solution if you already own a laptop, and have you seen ram prices? Also swapping to a fast SSD isn’t like it used to be on spinning discs. I’ve been amazed how responsive Mac neo laptops are and they are swapping all the time.
I'm not saying to avoid swap. It is great at what it was designed to do. I only take issue with optimizing swap for bandwidth when it will never be able to keep up with RAM bandwidth. The MacBook Neo for example has 60 GB/s of RAM bandwidth but only 1.5 GB/s SSD bandwidth.
Because it wouldn't soften the blow. Swap benefits the most from improved latency not bandwidth. Data is moved from swap back to physical RAM when swapped out pages are accessed by software (which stalls the thread). The kernel has less insight into the memory access pattern to prefetch the next page so the stalls likely continue for each page it needs to restore. The latency of zram (compressed in memory) is still lower than the fastest SSDs which reduces those stalls.
Russia stopped exporting diesel due to Ukrainian strikes. That badly hurt Turkey and to lesser extent Brazil. And Brazil started to get diesel from US allowing US companies to make a lot of profit. So Ukrainian strikes clearly affect global prices.
But then it also makes Chinese EV including trucks extremely attractive replacement. So China making a profit as well.
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