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Comment Re:Still not good enough. (Score 1) 357

Now, as to driving 8-10 hours without a stop, good luck. Worse, not even truck drivers are allowed to drive for that long without a break. In fact, they are required to take a minimum of a 30 minute break during any 8 hour period (i.e., they can not hit 8 hours of driving).

He didn't say he'd drive 8-10 hours without stop, just that he wanted to get that much actual driving in in a day. And IMO, that's short.

For example, take your trucker example. I'm not sure what that's supposed to be arguing, because 30 minutes every 8 hours is only even remotely approachable in the absolute best of conditions for the car (and awful conditions for the driver) -- 45 mph in 110 degree heat with no A/C running, according to Tesla's calculator. At 70 mph in a comfortable temperature, you'll barely be looking at 3 hours of driving off of a full charge. In that situation, even under unfairly favorable calculations for the Tesla, you'll be on the road about 85% of the time, which is about 3 times the breaks of the trucker.

The other problem is that driving conditions degrade the Tesla's performance dramatically. Conditions that would put the estimate at under 200 miles are reasonably common, and the most time-efficient way of driving is to only charge it partway, so you in poor-but-realistic conditions you could be looking at stops every 2 hours or less. (70 mph in even 32 degree temps with the heat on gives 196 miles. At 0 degrees it's 178. Let's say we're interested in 20 degrees, and guess 188. Increasing the speed by 5 mph decreases range by 10-15 miles, so let's say I'm interested in the range at 73 mph (this "may or may not" be my speed on the IN and OH turnpikes, for instance) and guess we're down to 180. Now multiply by 80% because of an incomplete charge, and you have 144 miles, or just a hair under two hours at 73 mph.)

Comment Re:Range anxiety isn't really rational (Score 1) 357

However, how many ppl drive their car more than 250 miles/day constantly?...Tesla will have a supercharger every 100 miles in the USA, so that you do not have to worry about that.

You don't have to do it constantly, just on occasion. For example, do you live in a city or live alone and only have one car? I don't know about you, but at least I wouldn't make it an electric. Even that 100-mile supercharger interval doesn't make it sound appealing for reasons I've said in another post: even the superchargers are too slow for long trips. "Just rent a car when you actually need to drive somewhere!" doesn't exactly make a good advertising slogan.

I'm very excited about electric cars now for commuting and very short trips, but once you get to the point of needing more than one charge on the road (which could happen in as little as ~5 hrs of driving in very realistic conditions -- really, even less than that) I think it starts to look really unattractive.

Comment Re:Range anxiety isn't really rational (Score 1) 357

Because that's really in their head, more than about any particular drive being possible.

It really isn't, at least from what I can tell, for long road trips. Even under the numbers from Tesla's range calculator you just can't make the same pace you can in a gas car even in reasonably forgiving conditions. In moderately hard but still very realistic conditions, it becomes even less favorable:

If you put in 70 mph and 32 degrees, you get 204 miles. And that's on a full charge. But that's not the most time-efficient way of charging -- better is to spend about 45 minutes charging to, IIRC, about 75-80% capacity. That drops you to 164 miles. So that's "drive for less than 2 1/2 hrs, charge for 45 minutes." That's making pretty poor time IMO.

And what about colder weather and, say, 75 mph (which their range calculator doesn't even go up to)? You could easily be driving less than 2 hrs between charges, even if the superchargers were placed perfectly.

I'm super optimistic about something like the Tesla for around-town driving and shorter trips. But for the longer ones... I think Tesla needs very good coverage with cheaper battery swaps than they are planning.

Comment Re:How about paying students after graduation? (Score 2) 321

It's a problem in the UK, that anyone competent in any computing or mathematical subject can earn at least double, sometimes as much as ten times as much working for a bank playing a huge zero-sum game as they can contributing to the economy. We used to have a brain drain to the US, now we have one to the City of London.

Comment Re:The exact goals, duration and budget... (Score 1) 88

Individual researchers are less likely to make significant contributions, but small teams still do. Individuals have ideas. Small teams produce proof-of-concept implementations. Larger teams produce working prototypes. Big teams produce finished products. It's hard to compete with a large company when it comes to bringing products to market, but it's quite easy for university research labs to get things to the proof-of-concept stage. They then have the choice of spinning out a company to try to commercialise it or licensing their work to a bigger company who will do the prototype to product bit.

Comment Re:I love ARM (Score 1) 88

That's an idea that predates MIPS. You'd do better if you claimed MIPS heritage because AArch64 removes the PC as a GPR, but (unlike MIPS) it does provide PC-relative addressing (MIPS does PC-relative memory accesses by forcing the calling convention to make every function call in position-independent code a JALR $25, so that $25 is guaranteed to contain the PC on function entry). MIPS also lacks the complex addressing modes of AArch64 (and AArch32). Unlike AArch64, it has branch delay slots, doesn't have the store/load pair instructions, condition code registers (all conditions in MIPS are stored in GPRs), bitfield manipulation instructions, and so on. ARM and MIPS are both derivatives of Berkeley RISC, but they have diverged a lot from that common inspiration.

Comment Re:I love ARM (Score 1) 88

Great for assembly programmers, not so great for pipeline designers. One of the weaknesses of the ARM design is that making the PC a general-purpose register meant that every instruction needs a little bit of extra logic in the decoder to tell you whether it's a branch, which then complicates the branch predictor. It's fun being able to do a ldr with the pc as the destination register, right up until you have to implement a long pipeline with that instruction. This is why ARMv8 makes the pc a special register (but still provides pc-relative loads and stores).

Comment Re:I love ARM (Score 1) 88

By having many different manufacturers there is no worry about ARM playing some games like cutting you off, or strongarming you into some new marketing ploy. If one manufacturer tries to screw you there are many others happy to do business.

This is part of ARM's strategy with ARMv8. They intentionally delayed their own designs so that they wouldn't compete with their partners. Now, if you want to license a 64-bit core from ARM, they have a low-power in-order design and a better-performing out-of-order superscalar design, but several of their partners also have their own ARMv8 implementations that were built with advice from ARM engineers but are independent implementations. They will each have different power/price/performance trades, helping to diversify the ARM ecosystem. Between multiple independent implementations of the core designs, and multiple potential companies to fab them, the ARM ecosystem is in quite a strong position.

Comment Re:Nvidia has NOTHING to lose at this stage (Score 3, Interesting) 66

The nVidia drivers on FreeBSD are pretty solid, but they got a poor reputation for their open source drivers in the early releases. I was running a room full of Linux boxes about 10 years ago, and they'd all kernel panic about once a day, typically while running nothing more strenuous graphically than the log-in screen, and always with a backtrace in the nVidia drivers. The open source ATi drivers of the same era (R200) were a lot slower, but were very stable.

nVidia also had that embarrassing incident where a crafted image could cause arbitrary code execution in the kernel, which turned out to be exploitable by just putting a picture on a web page, and didn't fix it until about two years after they were first notified of it. For the last 4-5 years, their proprietary drivers have been pretty reasonable though.

Comment Re:It doesn't offer free shipping (Score 1) 298

Is Amazon shipping more expensive in the US? I can't remember the last time I bought anything from Amazon that didn't come with free shipping. The only difference is that Prime gives you next day, whereas their super-saver free delivery gives you 3-5 days (typically closer to 3). I've found that if I need something very urgently then I will go into town and buy it - there are few situations where tomorrow is soon enough, but in a few days time is not.

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