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Comment Re: Title condradicts summary (Score 2) 143 143

No it really doesn't. Just because NVIDIA's marketing department calls something a core does not make it comparable to a CPU core - notice that even AMD's marketing is being more up front about this by talking about an APU having some number of "Compute units" which is the sum of the CPU cores and the GPU CUs.

Even if the GPU did have thousands of cores, though, that does not affect the numbers I discussed. Instead of having 32 cores with 64 ops per cycle you just get 32*64 cores with 1 op per cycle. You still only have a factor of 10 on ALU throughput.

Comment Re: Title condradicts summary (Score 1, Informative) 143 143

I honestly thought that we'd got away from this 500x nonsense a few years ago. I would suggest that AMD is one source for the information that 2-3 is more reasonable. AMD, Qualcomm, Khronos, any of the members of the OpenCL committee you talk to as well as NVIDIA insiders if you catch them at a conference. I gave multiple public talks countering any factors over about 10 when I worked at AMD, which were approved by management.

Just think the raw numbers through. The GPU has, say, 32 cores. The CPU ALSO has multiple cores. Don't count them, then you're cheating. So let's say we have 8 CPU cores there. Each CPU core has two SSE units or one AVX unit, to be conservative. That core is doing 8 ALU ops per cycle per core. So you have 64 ops per cycle. The clock rate is 3x the GPU so let's call it 196 ops per GPU cycle. The GPU had 32 cores. Each GPU core can do 64 ops/cycle (fair number for GCN). So you have 2048 ops/cycle on the GPU. 2048/196 is roughly 10. That's your peak - now you add in divergence costs on the wide GPU SIMD units (which statistically will hit you much earlier than with the CPU's narrow SIMD units), count the tiny GPU caches leading to more cache misses than the CPU and you can see why that factor of 10 invariably drops to 2 or 3x.

More honestly you're looking at a factor of 10 or so for ALU throughput, and 10 or so for memory throughput - and those are not multiplicative. In real use cases 2-3 is about right when comparing against well-optimised CPU code.

If there is a 500x speedup appearing with Libreoffice here, and the likelihood is that that is somewhat cherrypicked anyway, then what we are seeing is the difference between someone optimizing code and someone else not doing so. There is every reason to think the original code was only lightly optimized, not parallel, not vectorized or some set of the above.

Comment Re:Poor man's limo service (Score 1) 193 193

Try the same thing at Heathrow airport. You can take a metered taxi from the airport, but you can also request a private hire vehicle from the airport or (as I just did) book a car in advance to meet you in arrivals. In the US you might call that a limo service, but that usually implies a certain higher standard of car. In London we'd still call them taxis or cabs. We're talking about services that are significantly cheaper than private hire and cheaper than Uber as well based on the numbers I looked at.

Uber is little different from such a taxi dispatcher, the only real differences are that Uber is metered, and that Uber uses an app as opposed to grabbing a dispatcher phone number from the hotel lobby. If anything that metering and the roaming around waiting for the system to find you a job make Uber much more like a black taxi than like private hire in London.

Comment Re:Plain ol' C might a better option (Score 1) 296 296

std::vector a {1, 2, 3,4, 5};
for(int &v : a) {...}

Uses a reference, short and clean. Before C++11 the STL was a little copy constructor heavy, but only if you use it that way. If you use large objects, make your vector a vector of unique_ptr. It cleans up the data automatically when you delete the vector. On top of that, move construction/assignment should remove the majority of the cost of copying objects around in STL containers.

An STL implementation presumably could fairly easily optimise a vector> to a single type erased implementation, as long as the code that called delete had the type available. In the end you're trading code growth against pointer indirection and most evidence I've seen suggests that code growth is the smaller issue in the majority of code bases. I'm sure there are exceptions though.

Comment Re:Plain ol' C might a better option (Score 1) 296 296

It's more the association of destructors with objects that makes C++ different. Ensuring that a particular function is called when an object is destroyed needs compiler support. RAII is a huge benefit of C++ over C. Although admittedly it is most important in the context of exceptions, which are themselves a C++ feature.

Comment Re:Expect an updated U.S. travel advisory. (Score 1) 28 28

Right. It's a pleasant experience for an organised tour. From the tourist point of view much less of a hell hole than all sorts of places you can visit in more liberal countries - including poorer parts of the US. Of course, in a large part that's because they are presenting an image to try to make the place seem better than it really is. In reality they do a good enough job to make the tour pleasant, but not a good enough job to make you come away thinking it's the utopia they would like to make out - the reality is pretty hard to hide. You can get enough of a gist of what they don't want to show you to see something of the underlying situation.

The US takes a far harder line on NK travel advice than other countries do. Partly because the authorities really do dislike the US and have been known to take that out on American citizens. Partly presumably for the same underlying reason the US has such a harsh line on travel to Cuba that other countries do not have. After all, I don't think many people outside the US believe the Cuba travel/spending ban is intended to benefit Cubans. There were Americans on our tour, though, and they were well treated. This was all long enough ago that they still held mobile phones at the airport, but my understanding is that rules have relaxed considerably since then both in terms of phones and freedom to leave the hotel without a guide.

The bigger challenge with travel to NK is the ethical question about giving money to the authorities there when paying for travel in the first place. We were torn on that for a long time before deciding to go. In the end we decided to largely because it would be better to see something of it than to jump to conclusions.

Comment Re:The problem with older developers... (Score 1) 429 429

Often even up to VP level. Other companies treat management as an optional add on to a technical role up to some fairly high level in the organisation. It still depends a lot on what you want to do, though. Few of those Fellow/Director of Technology/whatever other tech track title roles at the high level end up really having a lot of coding. You're exchanging making decisions about people for making decisions about projects.

Comment Re:nonsense (Score 1) 532 532

That is true, but maybe one reason for that is that only people the government doesn't care about, democratically speaking, suffer from it. The NHS in the UK affects almost all voters, even most middle class people use it for most things, and so there is more incentive to keep a reasonable standard of service. It also means the service for the very poor is integrated with the service for everyone else, so you don't end up in the same situation of a doctor restricting NHS patients in favour of private ones to anything like the same degree you see with medicaid.

Dental care is a bit of an exception, but in part that is because while dental bills get high they don't generally reach bankruptcy levels in the way hospital bills do. A lot of UK dentist have dropped support for NHS dental treatment for adults. Not for children, though, which is probably why the UK rates so well on dental health.

Comment Re:nonsense (Score 1) 532 532

Have your French cousins experienced American healthcare? One of the big things British and French expats miss when living in the US is the healthcare.

If you are wealthy and have good private insurance, then American healthcare works well. British and French top up insurance and private care is comparable, though. If you are not rich, and had to rely on the government healthcare in Europe, then the American version is inferior.

Comment Re:nonsense (Score 1) 532 532

Before even reaching single payer, there needs to be a legal requirement for a single charger! If you go to a particular doctor for treatment, ALL bills should come from that doctor or his facility. If they contract, that doesn't matter, that doctor is responsible for telling you how much you owe, being in-network with the insurance companies and so on. The current situation of going to an in-network doctor only to find he uses an anaesthetist or lab who is out of network and thus only partially covered is insane.

Comment Re:stupidly weak (Score 2) 267 267

Your first word is 7 digits your second is 3, so clearly one is stronger than the other. "nom" is not in the diceware set, which helps a little, but it isn't so uncommon to be in a search dictionary. The numbers are in the diceware set.

You're comparing 7700^3 against 7700^7. Your more secure password isn't any better than chickensandwichwafflesworkcraigcrossafrica, probably a lot less good because chicken, delicious and nom clearly correlate heavily and nomnomnom is almost one word really. 7700^7 is 1604852326685300000000000000 according to my calculator. If I assume 72 characters (52 letters, 10 numbers, 10 special characters) then I need a 15 character random password to beat it in terms of search space. Maybe this: }&X$0ueUo~ravx&.

Further, if you put numbers between your letters you are turning a search space of 7700 into 7710 or whatever. If you replace l with 1 and so on, you are surely turning 7700 into 7700*(number of replacement options and combinations thereof). So mathematically, I would think that replacing e with 3, a with @ would actually be a stronger encoding that what you suggest.

"Why waste negative entropy on comments, when you could use the same entropy to create bugs instead?" -- Steve Elias

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