I bought an SD card assuming that it would *not* be smart enough to do levelling. But it was fairly cheap...
And there are Linux filesystems that are designed to be wear-levelling, but I wanted one that I could simply dd from the HDD master if the memory card failed. After months of use I see no trouble at all so far. I'm sure that laptop-mode makes any enormous difference by consolidating writes.
I already boot/run my main Internet-facing server (Ubuntu) from a 4GB memory SSD card to minimise power consumption, and I have more than 50% space free, ie it wasn't that hard to do.
I'm not being that clever about it: using efs3 rather than any wear-leveling SSD-friendly fs, and simply minimising spurious write activity, eg by turning down verbosity on logs. And laptop-mode helps a lot of course.
Now that machine does also have a 160GB HDD for infrequently-accessed bulk data (so the HDD is spun down most of the time and a power-conserving sleep mode), and it would be good to get that data onto SSD too. But a blend, as in many memory/storage systems, gives a good chunk of maximum performance and power savings for reasonable cost.
Very gracious of you to respond at all, and thanks for the explanation! I'm really not knocking your technology but it is important that everyone realises that you've not built a perpetual motion machine ('overunity' etc) since people are already hyperventilating and claiming that you have, and thus the claims really should be more carefully worded IMHO. But I also realise that if you're too cautious no one will even look!
If there really is a way I could test one out for you alongside the MotorWind and a couple of other micro solutions, I'd be pleased to help though I am no specialist with glowing credentials: you have my contact details. I will check out your site at the time that you suggest.
Again, not all turbines, and the text seemed to be claiming 30x better than the *best*, which for honesty/fairness had better be the best at the same windspeeds.
Look at designs like simple VAWTs and the MotorWind HAWT for low wind speeds, rather than the more conventional HAWTs.
*All* designs suffer from the wind's power varying with the cube of the wind-speed.
And unlike a VAWT or yawed-HAWT, the Microwind looks like it needs a fixed wind direction *and possibly a narrow fixed speed range* for the vibrations to be set up.
Doesn't mean it isn't interesting: I'd love to play with one!
Well, one reason that I'd dearly like to get a simple VAWT (Vertical Axis Wind Turbine) working is to eliminate two expensive parts for low-power applications: the mast (or at least most of it) and the yaw brearing.
No gearbox required, and the blades can be cut out of a strong weatherproof box.
But, yes, the generator is still expensive. Two costs (the strong magnets, and the wound coils) is shared with the Microwind.
...but it is not at all clear what their efficiency or $/Watt or manufacturing cost will be. Although absolute efficiency is maybe not critical for many applications given that the wind is free, cost is important in, for example, third-world deployments.
Much as I'm intrigued by this let's not get into perpetual motion machines nor "beating Betz" just yet! In particular the "30x as efficient as the best microturbines" claim in TFA is particularly suspect: I have a VAWT made from a cardboard cereal packet in my back garden that probably extracts 10% of the available energy.
Tracking and receiving diffuse light don't necessarily make a great deal of difference all the time anyway, as I should have said, eg a flat panel at 75* from the horizontal in London (England) will get most of what mid-winter light there is to have anyway, except in really cloudy weather when maybe facing stright-up would be better.
I'm not especially advocating mechanical tracking, I'm just not convinced that the invention described will capture any more than the other solutions I mentioned because of shadowing of some cells by others, for example.
For example, the statement about solar panels not having to be flat already applies: there are flexible, stickable (see the UniSolar laminate for example) ones now, with Fresnel lenses etc.
In fact, for many uses, solar is easily laid on an existing flat surface such as a roof. Flat is very often convenient.
The issue about capturing light from any angle is only valid if the individual cells/balls and their connectors (and any surrounding obstacles such as walls and trees) don't get in the way. Multi-layer cells and mechanical trackers and even mirrors mitigate these problems in existing systems: http://www.earth.org.uk/note-on-solar-PV-for-diffuse-light.html
Anyway, interesting, and it would be good to test some in places like the tops of walls, roof ridges, pathways, etc.
Basically I replaced my entire 670W rack of Web-facing servers at home with a single Linux laptop that uses ~18W off 12V DC (+7W wasted in the mains adaptor), which sometimes now runs off-grid on solar PV so that 12V DC power figure is meaningful.
I have no reason to believe that my situation is really exceptional, and I'm running a fairly standard mix of servers (NTP, SMTP, DNS, HTTP both flat-file and Java-based)...
Interesting that the AdSense medium (along with its counterpart, AdWords) now supports diverse charging models CPM/CPC/CPA as well as all these different media. I'm a bit of a YouTube skeptic, but maybe G will make it a little more grown-up and useful with things like this!
Except that under example.mobi users can have some confidence that appropriate mobile-friendly standards will be externally enforced, not what some uber-designer with CSS and Flash on the brain decides 'will do' on mobi.example.com. Simple things like if there is a www.example.mobi then example.mobi must exist too. And not SENDING huge pages with crap in that the mobile handset has to pay for but then ignore.
That's why I set up my.mobi site alongside my main one, to present a more appropriate (read: smaller, faster, search box at the bottom) view for mobile browsers. I don't have to guess or translate anything and nore does Vodafone: for this URL I generate.mobi-compliant XHTML straight off.
Other than V managing to content block me from one of my own sites in Australia for a while (even though I have content blocking turned off and there's nothing dodgy about the site) their service seems to work quite well. I don't like stuff being redirected via a 'transparent' proxy, but maybe I could use SSL to prevent that if I really cared I guess.
Hmm, looked at FPGAs too. Not generally worth the highly-specialised one-off development even when writing your own code.
Much nicer to have something portable which next year will just run faster without your doing much because of an improved compiler, runtime, CPU, cache, bus, kernel, whatever... Usually...
It's clear that the nature of my app (which is in Java, BTW) is going to make a difference, and I've not seen quite this effect before in Java or C++ threading over 10+ years where I've had to run well short of a thread per CPU to maximise throughput or at least throughput per CPU. The threads are moderately tightly coupled but, as I say, rarely sharing mutable state. Usually running with a few too many threads to allow for a little parallel slackness is a better bet.
Part of the problem in my particular app is more subtle in that the nature of the app is forcing more GC than I normally allow, and that *is* much less paralleliseable in practice, even on JDK 6u2 with -Xconcgc...
I have spent a long time looking for my screw-up in this app, I just haven't found it yet!
Well, what's nice about my Niagara T1000 box is that everything is on one chip, and the outermost level of cache serves all CPUs, so even a nominal cache flush for volatile/synchonized never need leave the chip and hit real RAM.
I'm just concerned that threading seems poor when you really do have to go to memory to get data between CPUs, and your idea of giving up some individual cache for some shared cache would be quite right if Intel had the engineering time to do it.
For my latest nasty performance surprise on the Xeons I had to run only a couple of threads rather than 4 (one per CPU), even for entirely CPU-bound work not sharing any significant writable state, I guess to keep everything on one chip and away from main memory.
Very frustrating, but maybe just getting me in practice for real NUMA/threading a few years down the road... B^>
My recent experience with quad-CPU Xeon machines is that multithread performance for a single is VERY poor, even with great care in coding, presumably because of cache-sloshing between these physically-separate CPUs dropped onto one die.
(I compare with Niagara and even Core Duo which seem much better for threaded apps.)
Has anyone else tested threadability of these CPUs, and power efficiency, sleep states, etc?
They are presumably *allowed* to put him in jail and deny him all Internet access, so, yes, they could probably even make him use VGA with a nasty colour scheme.
In his case I might decline to use Windows for security and cost reasons until the sentence was complete, but maybe ask to be able to use court-supplied facilities to check email.
I don't understand your 'multi-junction is expensive' point. I have a UniSolar ES62 multijunction amorphous panel sitting out in my garden right now because it was the *cheapest* W/£ that I could buy.
Slashdot Mirror
I bought an SD card assuming that it would *not* be smart enough to do levelling. But it was fairly cheap...
And there are Linux filesystems that are designed to be wear-levelling, but I wanted one that I could simply dd from the HDD master if the memory card failed. After months of use I see no trouble at all so far. I'm sure that laptop-mode makes any enormous difference by consolidating writes.
Rgds
Damon
Hi,
I already boot/run my main Internet-facing server (Ubuntu) from a 4GB memory SSD card to minimise power consumption, and I have more than 50% space free, ie it wasn't that hard to do.
http://www.earth.org.uk/low-power-laptop.html
I'm not being that clever about it: using efs3 rather than any wear-leveling SSD-friendly fs, and simply minimising spurious write activity, eg by turning down verbosity on logs. And laptop-mode helps a lot of course.
Now that machine does also have a 160GB HDD for infrequently-accessed bulk data (so the HDD is spun down most of the time and a power-conserving sleep mode), and it would be good to get that data onto SSD too. But a blend, as in many memory/storage systems, gives a good chunk of maximum performance and power savings for reasonable cost.
Rgds
Damon
Hi Shawn,
Very gracious of you to respond at all, and thanks for the explanation! I'm really not knocking your technology but it is important that everyone realises that you've not built a perpetual motion machine ('overunity' etc) since people are already hyperventilating and claiming that you have, and thus the claims really should be more carefully worded IMHO. But I also realise that if you're too cautious no one will even look!
If there really is a way I could test one out for you alongside the MotorWind and a couple of other micro solutions, I'd be pleased to help though I am no specialist with glowing credentials: you have my contact details. I will check out your site at the time that you suggest.
Rgds
Damon
Which might be true, and is very interesting if so, but then they should say that and/or back it up!
I really do think that there is a dearth of solutions in the sub-100W range, and this looks potentially interesting.
Not everyone is wanting to run a 3kW electric oven in their off-grid shack...
Right now I'm working by a single 3W LED in my office, and I only need ~20Wh/day to cover its consumption for example.
Rgds
Damon
Again, not all turbines, and the text seemed to be claiming 30x better than the *best*, which for honesty/fairness had better be the best at the same windspeeds.
Look at designs like simple VAWTs and the MotorWind HAWT for low wind speeds, rather than the more conventional HAWTs.
*All* designs suffer from the wind's power varying with the cube of the wind-speed.
And unlike a VAWT or yawed-HAWT, the Microwind looks like it needs a fixed wind direction *and possibly a narrow fixed speed range* for the vibrations to be set up.
Doesn't mean it isn't interesting: I'd love to play with one!
Rgds
Damon
Well, one reason that I'd dearly like to get a simple VAWT (Vertical Axis Wind Turbine) working is to eliminate two expensive parts for low-power applications: the mast (or at least most of it) and the yaw brearing.
No gearbox required, and the blades can be cut out of a strong weatherproof box.
But, yes, the generator is still expensive. Two costs (the strong magnets, and the wound coils) is shared with the Microwind.
Rgds
Damon
...but it is not at all clear what their efficiency or $/Watt or manufacturing cost will be. Although absolute efficiency is maybe not critical for many applications given that the wind is free, cost is important in, for example, third-world deployments.
See the discussion here for example: http://www.fieldlines.com/story/2007/10/13/9445/4984
Much as I'm intrigued by this let's not get into perpetual motion machines nor "beating Betz" just yet! In particular the "30x as efficient as the best microturbines" claim in TFA is particularly suspect: I have a VAWT made from a cardboard cereal packet in my back garden that probably extracts 10% of the available energy.
Rgds
Damon
Tracking and receiving diffuse light don't necessarily make a great deal of difference all the time anyway, as I should have said, eg a flat panel at 75* from the horizontal in London (England) will get most of what mid-winter light there is to have anyway, except in really cloudy weather when maybe facing stright-up would be better.
I'm not especially advocating mechanical tracking, I'm just not convinced that the invention described will capture any more than the other solutions I mentioned because of shadowing of some cells by others, for example.
Rgds
Damon
For example, the statement about solar panels not having to be flat already applies: there are flexible, stickable (see the UniSolar laminate for example) ones now, with Fresnel lenses etc.
In fact, for many uses, solar is easily laid on an existing flat surface such as a roof. Flat is very often convenient.
The issue about capturing light from any angle is only valid if the individual cells/balls and their connectors (and any surrounding obstacles such as walls and trees) don't get in the way. Multi-layer cells and mechanical trackers and even mirrors mitigate these problems in existing systems: http://www.earth.org.uk/note-on-solar-PV-for-diffuse-light.html
Anyway, interesting, and it would be good to test some in places like the tops of walls, roof ridges, pathways, etc.
Rgds
Damon
More than a factor of four in my case (more than 20x by some narrow measures):
http://www.earth.org.uk/low-power-laptop.html
and
http://www.earth.org.uk/saving-electricity.html
Basically I replaced my entire 670W rack of Web-facing servers at home with a single Linux laptop that uses ~18W off 12V DC (+7W wasted in the mains adaptor), which sometimes now runs off-grid on solar PV so that 12V DC power figure is meaningful.
I have no reason to believe that my situation is really exceptional, and I'm running a fairly standard mix of servers (NTP, SMTP, DNS, HTTP both flat-file and Java-based)...
Rgds
Damon
Interesting that the AdSense medium (along with its counterpart, AdWords) now supports diverse charging models CPM/CPC/CPA as well as all these different media. I'm a bit of a YouTube skeptic, but maybe G will make it a little more grown-up and useful with things like this!
Glossary: http://www.publisher-world.com/read.php?12,10879,10879#msg-10879
Rgds
Damon
...I'm afraid that's the nearest I've seen to a simulated pissing contest ever! B^>
Rgds
Damon
Simply not true. The Treasury/BoE agreed to underwrite the NR deposits in place at the time of the 'run'. Nothing else and for no other bank.
I'm pleased that NR has suffered for its poor business practices, and I'm pleased that by-and-large its customers will not.
Rgds
Damon
It is part of the guidelines/agreement for .mobi use, eg see:
http://mtld.mobi/domain/policies/compliance
http://www.w3.org/TR/mobile-bp/
http://ready.mobi/results.jsp?uri=http%3A%2F%2Fsmlpx.mobi&locale=en_EN
I don't know if the boot has been put in yet for non-compliance, but I hope it is.
The best practices guide referenced specifies page weight, default media types, etc.
Rgds
Damon
Except that under example.mobi users can have some confidence that appropriate mobile-friendly standards will be externally enforced, not what some uber-designer with CSS and Flash on the brain decides 'will do' on mobi.example.com. Simple things like if there is a www.example.mobi then example.mobi must exist too. And not SENDING huge pages with crap in that the mobile handset has to pay for but then ignore.
Rgds
Damon
That's why I set up my .mobi site alongside my main one, to present a more appropriate (read: smaller, faster, search box at the bottom) view for mobile browsers. I don't have to guess or translate anything and nore does Vodafone: for this URL I generate .mobi-compliant XHTML straight off.
Other than V managing to content block me from one of my own sites in Australia for a while (even though I have content blocking turned off and there's nothing dodgy about the site) their service seems to work quite well. I don't like stuff being redirected via a 'transparent' proxy, but maybe I could use SSL to prevent that if I really cared I guess.
Rgds
Damon
Hmm, looked at FPGAs too. Not generally worth the highly-specialised one-off development even when writing your own code.
Much nicer to have something portable which next year will just run faster without your doing much because of an improved compiler, runtime, CPU, cache, bus, kernel, whatever... Usually...
Rgds
Damon
Yes, I too think that the GPL rates RMS' political agenda higher than my creative contribution, so I prefer BSD licensing.
It's not like RMS is paying me, so why should my work be used to support his aims above mine?
Rgds
Damon
It's clear that the nature of my app (which is in Java, BTW) is going to make a difference, and I've not seen quite this effect before in Java or C++ threading over 10+ years where I've had to run well short of a thread per CPU to maximise throughput or at least throughput per CPU. The threads are moderately tightly coupled but, as I say, rarely sharing mutable state. Usually running with a few too many threads to allow for a little parallel slackness is a better bet.
Part of the problem in my particular app is more subtle in that the nature of the app is forcing more GC than I normally allow, and that *is* much less paralleliseable in practice, even on JDK 6u2 with -Xconcgc...
I have spent a long time looking for my screw-up in this app, I just haven't found it yet!
Rgds
Damon
Well, what's nice about my Niagara T1000 box is that everything is on one chip, and the outermost level of cache serves all CPUs, so even a nominal cache flush for volatile/synchonized never need leave the chip and hit real RAM.
I'm just concerned that threading seems poor when you really do have to go to memory to get data between CPUs, and your idea of giving up some individual cache for some shared cache would be quite right if Intel had the engineering time to do it.
For my latest nasty performance surprise on the Xeons I had to run only a couple of threads rather than 4 (one per CPU), even for entirely CPU-bound work not sharing any significant writable state, I guess to keep everything on one chip and away from main memory.
Very frustrating, but maybe just getting me in practice for real NUMA/threading a few years down the road... B^>
Rgds
Damon
My recent experience with quad-CPU Xeon machines is that multithread performance for a single is VERY poor, even with great care in coding, presumably because of cache-sloshing between these physically-separate CPUs dropped onto one die.
(I compare with Niagara and even Core Duo which seem much better for threaded apps.)
Has anyone else tested threadability of these CPUs, and power efficiency, sleep states, etc?
Rgds
Damon
They are presumably *allowed* to put him in jail and deny him all Internet access, so, yes, they could probably even make him use VGA with a nasty colour scheme.
In his case I might decline to use Windows for security and cost reasons until the sentence was complete, but maybe ask to be able to use court-supplied facilities to check email.
Rgds
Damon
Hi,
He claims that this story is not true as told: it's simply that the statisticians don't want to be jumped by journalists. Which I could understand.
I'm urging him to login and post the agency's view. Quickly. Before we all move back to the next **AA/NASA/Sony/Sun/Dell/whatever misadventure...
Rgds
Damon
Sometimes.
But sometimes space is at a premium and that is what you need to optimise for, such as my current application.
Rgds
Damon
I don't understand your 'multi-junction is expensive' point. I have a UniSolar ES62 multijunction amorphous panel sitting out in my garden right now because it was the *cheapest* W/£ that I could buy.
Rgds
Damon