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Comment: Re:Help me out here a little... (Score 1) 496

by dgatwood (#49517525) Attached to: Utilities Battle Homeowners Over Solar Power

Let's take water as our analogy. Water flows to meet demand in the form of open taps. But very few of those taps are strictly regulating, and the outflow is a function of how far the tap is opened and the pressure in the system. Put more water into the mains and the pressure goes up, therefore more water is delivered at the tap. If your house has pressure regulating valves, you won't see this, but the pressure is then further increased at someone else's house.

That analogy doesn't really work very well, for two reasons:

1. Water pressure is more closely equivalent to voltage, not amperage. Adding more solar panels increases the amperage, not the voltage.

2. Most electrical equipment is strictly regulating (ignoring inrush). Resistive loads consume a consistent amount of current regardless of how much current is available. That's why it doesn't matter whether you power a 12V bulb with eight AA batteries or a 12V car battery. The latter can provide a lot more current, but the bulb still draws just as much current as it needs.

I think a better analogy is to think of the voltage as the height of a water tower, and the amperage as its diameter. If you have a ten-foot-diameter tower that forms a 50-foot column of water, the pressure is proportional to the 50-foot height of the water column. An overheating condition would be equivalent to the pipe breaking because someone is sucking water out of the pipe faster than the pipe can pass it.

If you expand the tower to be thirty feet in diameter, the column is still about 50 feet high, so the pressure is about the same (assuming the sides of the tank are vertical and the bottom is flat). However, doing so allows you to add more pipes and/or larger pipes out the bottom so you can provide water to more houses without drawing down the reservoir too quickly (and thus causing... what, a vacuum in the water tower? This is where the analogy starts to break down unless you're talking about a battery).

Comment: Re:Billionaire saved by taxpayer (Score 1) 110

Among all the companies in that program the default rate was very low. Solyndra was the only noteworthy default. The DOE made a solid overall profit on the program. It was indisputably a successful program.

No, it isn't "indisputably a successful program". http://www.forbes.com/sites/ti...

Every cent of money funding this loan program was taken from a US citizen who could have been using it for some superior performing personal investment.

Comment: Re:Billionaire saved by taxpayer (Score 1) 110

Any loan program will have failures. I remember during the 2012 election Rupublicans said Obama was terrible, because fed loans made under him had a 20% bankruptcy rate. But hailed Romney as a business hero even though under his leadership Bain Capital had a 50% bankruptcy rate. The numbers aren't as bad as people make out for either; that's how these things work. We can't act like the sky is falling over some failures.

Taxpayer money, collected involuntarily ... versus private capital, collected voluntarily from people who wanted to risk their money chasing profits.

Are you unable to notice a simple, fundamental difference in the source of money?

I'll also note that your metric of success for the loan program is simply wrong. It's not measured by bankruptcy rate ... but net profit. Profit means that overall, the money was productive; bankruptcy in of itself is not relevant.

And the feds don't need to make back all their money via repayment. As the other poster said, Tesla is still paying US taxes and hiring US workers. The feds get money off that too. The feds didn't need to recoup all losses simply by repayment since they gain (maybe more so) by having a successful company.

It has not been shown that federal interference produced a better outcome than if Google had simply bought Tesla out.

If you want to justify federal loans, that's what you need to prove.

Comment: Re:Baptists are already writing this week's sermon (Score 0) 37

by Ol Olsoc (#49516957) Attached to: 3.46-Billion-Year-Old 'Fossils' Were Not Created By Life Forms

Nothing has been overturned here. Just a question settled, perhaps.

And this is the difference between science and religion. Since its science, we say, "we were wrong - but its cool, now we can move on to find out the truth..

If this were religion, we'd be fighting tooth and nail, and there would be smear jobs about the scientists liberal tendencies, and stories going around on "How the lord said life was 3.46 billion years old, so it damn well WAS 3.46 million year old fossils.

Teach the controversy brothers!

Comment: Re:Matlab (Score 1) 130

by Jeremi (#49516469) Attached to: Swift Tops List of Most-Loved Languages and Tech

there has to be a good reason for it, and making it easier for bad programmers to produce more bad code is not a valid one.

If all you've got is bad programmers, and their bad code is nevertheless good enough to accomplish the tasks you need to get done, then a tool that allows bad programmers to produce more bad code may be just the thing you need. (of course some would argue that that niche is already filled by Java, but time will tell)

Comment: That's because they're not much faster (Score 5, Insightful) 119

by Solandri (#49515937) Attached to: New PCIe SSDs Load Games, Apps As Fast As Old SATA Drives

Slashdot has covered a bunch of new PCI Express SSDs over the past month, and for good reason. The latest crop offers much higher sequential and random I/O rates than predecessors based on old-school Serial ATA interfaces.

That's just it. Their speeds are not "much higher." They're only slightly faster. The speed increase is mostly an illusion created by measuring these things in MB/s. Our perception of disk speed is not MB/s, which is what you'd want to use if you only had x seconds of computing time and wanted to know how many MB of data you could read.

Our perception of disk speed is wait time, or sec/MB. If I have y MB of data I need read, how many seconds will it take? This is the inverse of MB/s. Consequently, the bigger MB/s figures actually represent progressively smaller reductions in wait times. I posted the explanation a few months ago, the same one I post to multiple tech sites. And oddly enough Slashdot was the only site where it was ridiculed.

If you measure these disks in terms of wait time to read 1 GB, and define the change in wait time from a 100 MB/s HDD to a 2 GB/s NVMe SSD as 100%, then:

A 100 MB/s HDD has a 10 sec wait time.
A 250 MB/s SATA2 SSD gives you 63% of the reduction in wait time (6 sec).
A 500 MB/s SATA3 SSD gives you 84% of the reduction in wait time (8 sec).
A 1 GB/s PCIe SSD gives you 95% of the reduction in wait time (9 sec).
The 2 GB/s NVMe SSD gives you 100% of the reduction in wait time (9.5 sec).

Or put another way:

The first 150 MB/s speedup results in a 6 sec reduction in wait time.
The next 250 MB/s speedup results in an extra 2 sec reduction in wait time.
The next 500 MB/s speedup results in an extra 1 sec reduction in wait time.
The next 1000 MB/s speedup results in an extra 0.5 sec reduction in wait time.

Each doubling of MB/s results in half the reduction in wait time of the previous step. Manufacturers love waving around huge MB/s figures, but the bigger those numbers get the less difference it makes in terms of wait times.

(The same problem crops up with car gas mileage. MPG is the inverse of fuel consumption. So those high MPG vehicles like the Prius actually make very little difference despite the impressively large MPG figures. Most of the rest of the world measures fuel economy in liters/100 km for this reason. If we weren't so misguidedly obsessed with achieving high MPG, we'd be correctly attempting to reduce fuel consumption by making changes where it matters the most - by first improving the efficiency of low-MPG vehicles like trucks and SUVs even though this results in tiny improvements in MPG.)

Comment: Re:ISTR hearing something about that... (Score 1) 119

by Jeremi (#49515815) Attached to: New PCIe SSDs Load Games, Apps As Fast As Old SATA Drives

it actually caused a bug that would crash the system

It would be more accurate to say it revealed a bug. The bug was almost certainly a race condition that had always been present, but it took particular entry conditions (such as an unusually fast I/O device that the transcoder developers never tested against) to provoke the bug into causing a user-detectable failure.

Comment: Re:Interstate Water Sharing system (Score 1) 589

by Ol Olsoc (#49515499) Attached to: William Shatner Proposes $30 Billion Water Pipeline To California

That was my actual point. Sarcasm or hidden irony doesn't translate well to the web.

As soon as someone who didn't know that California already sucked that river dry, and checked my statement out, they might start to understand just why other states might not care to give all of their own water to California.

Comment: Re:ISTR hearing something about that... (Score 1) 119

by gstoddart (#49515367) Attached to: New PCIe SSDs Load Games, Apps As Fast As Old SATA Drives

On a PC environment when you've got multiple browser windows open, IRC, email client, etc. getting constrained for IOPS is easier than expected.

Generally, I would say that machine would only be IO bound if it had so little memory it was constantly paging.

Those things once loaded are NOT doing heavy disk IO. Heavy disk IO would be thrashing in all likelihood.

So you add more RAM. You'd be amazed how many "IO" problems can be fixed with eliminating the IO in the first place by adding RAM.

Comment: Re:Billionaire saved by taxpayer (Score 1) 110

Getting taxpayers a profit proportional to the lending risk they assumed is not "fucking [Tesla] in the ass".

The loan program also lends money to epic failures like Solyndra - if they don't maximize their profits on the better investments, they won't cover the costs on the bad ones.

Federal tax money is not a personal piggy bank for your favorite CEO/corporation. "Socialized risk and privatized profit" ring a bell?

Comment: So, where is the EULA? (Score 1) 403

by bobbied (#49515137) Attached to: Automakers To Gearheads: Stop Repairing Cars

Ok, automakers want to force me to obey their license terms? WHERE ARE THEY?

I've never had a dealer make me sign a EULA or license terms to use the car they just sold me... Go ahead guys, TRY IT!.

Once you do this, I'm going to review all the software I can find in my car and start looking for Open Source libraries in all that fancy user interface stuff you are providing now and make you comply to the license terms for it all. I have a feeling that we will find that you have some legal problems..

Next they are going to try this on hand tools....

Comment: Can't say I love it *yet*. (Score 1) 130

by jcr (#49515131) Attached to: Swift Tops List of Most-Loved Languages and Tech

Coming from many years of Obj-C development, I can acknowledge several ways in which Swift is superior, but the learning curve is somewhat steeper than the transition from C to Objective-C was.

Aside from the language itself, Swift playgrounds are wonderful. We're getting closer all the time to a Smalltalk way of writing code.

-jcr

Comment: This is the long way to say... (Score 1) 119

by bobbied (#49515031) Attached to: New PCIe SSDs Load Games, Apps As Fast As Old SATA Drives

We've reached the limits of the flash technology which drives both the SATA and PCIe versions of the storage device, at least in terms of how fast the data can be received from the media (the nand flash). This is not surprising. Flash is not all that fast and it quickly becomes the limiting factor on how fast you can read data out of it.

Just moving from SATA to PCIe wasn't going to change the underlying speed of the media. The slowest device in the chain is what rules the overall speed. We've just moved past where the drive interface is the limiting factor.

So the story here really is, that we have reached the limits on the Nand Flash, at least on read performance.

"If you own a machine, you are in turn owned by it, and spend your time serving it..." -- Marion Zimmer Bradley, _The Forbidden Tower_

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