I don't know. But virtual is probably divided amongst its users, eg a 1MB shared lib by ten processes is probably 100kB accounted to each, and conversely RAM may include file cache or transient anonymous areas; you'll have to RTFM I think.
Mapping a file into memory, for example a shared library, even read-only, may show up in the 'virtual memory' usage. But it's not taking any actual memory away from anything else to do that except easily-dropped file/page cache. Sun got burnt when users claimed that Java was suddenly 'using more memory' just because they mmap() the JARs as I recall, but it makes no real difference to what's available to other apps I believe.
I went to see the vendor at its office because it had some interesting stuff on sale, and discussing what they were working on stumbled upon this LiFePO4 battery. It's prismatic (so compact) and has a BMS built in, suitable to accept nominal 12V solar PV directly at its inputs. (It has 4 wires; PV in and nominal 12V out, though a common +ve rather than -ve which is a slight nuisance.) BMS, ie solar charging of Li, was my big worry at the time.
Um, you're posting in/. where precision is a good thing. You must be new here! B^> Your initial statement was palpably false and silly; your new one is fine (though I may still not agree with it).
Getting like to compare with like is astonishingly difficult post hoc in my experience, but I did it many many years for a defence company and was able to project commodity CPU performance forward about a decade (it turned out) across families and within a single family (x86) reasonably well.
Probably few journalists have the time to embark on building such curves from scratch, though I agree that they are interesting.
Maybe do some yourself and stick them in Wikipedia?
It works for me. Maybe it wouldn't do for you, I can't tell.
But as I actually enjoy the challenge of working with resource-constrained 'embedded' systems (my first job was designing and implementing a robotic OS and hardware 25+ years ago), this part of the fun.
Nobody? Not ever, not one single sheet? Not like how I use almost all the paper that comes to my house for notes, or the kids to draw, etc, on *before* recycling it or using in the compost heap?
OK, clearly I must be imagining using my paper 2 or 3 times typically. And printing almost nothing out of my own.
It's entirely fast enough for my purposes: I have front-end mirrors and CDN to serve data quickly to end users. It also handles my mail (including many thousands of SPAMs per day), and SVN and so on.
And it does mean that I've been able to run the entire system off-grid, on a few solar panels propped up against a wall! B^>
That might even be worth it (per kWh) for some apps, such as smart phones. B^>
Unless it's 6x--8x per l or kg in which case that's be the same price per kWh as the current lot (but a lot smaller and longer-lasting) and would be *wonderful*! I could run my house for a year on a small shed's worth!
I don't think you've been doing it right and having enough fun! I've experienced plenty of catastrophic HDD failures with little warning or possible recovery, including my last MacBook's internal HDD killed pretty abruptly by static AFAIK. (I managed to recover my SSH key, but that was about it.)
Running a busy USENET server (I think I hovered at ~#10 in the stats for while) used to wear out normal hard drives too, back in the day; SSDs aren't especially novel in that regard IMHO. It's really only a matter of how frequent and comprehensive your backups are.
And as my USENET data didn't last longer than about a week then I think I regarded backups as largely pointless except for some very low-traffic local groups and just threw away a drive when it died and let the new one fill up again!
BTW, I've been running a server entirely on a mixture of SD cards and USB Flash for a couple of years so far, so good. I have taken efforts to reduce spurious writes but I still make sure that I have backups of critical stuff elsewhere: http://www.earth.org.uk/note-on-SheevaPlug-setup.html
Hmm, I see a whole new slew of SPAM: "Need your anode volumetrically gifted? Feeling that your capacity is down or resistance to your action is going up, unlike you? Our new CiaLIaSi is for you!"
I do read NS, as it happens. I even write vaguely technical stuff for money sometimes.
But spending your effort to whinge about/.'s climate being the wrong shade of purple in the latter part of an autumnal afternoon in your backyard is just a waste of everyone's effort. Just don't read TFA/TFS/TFC and spare us your peccadilloes, please.
What fraction of the entire cell is the anode, and thus how much 'sometimes unused' space has to be left for this anode when fully turgid, and thus by what fraction does this knock down Wh/l energy density, do you think?
Anyhow, it seems as if it might be quickly commercialisable and just needs a matching top-notch cathode! B^>
Maybe *you* only want to know about things once they are no longer R&D and are just lumpen consumer goods available in your local B&M.
Others may like to know about research, both blue-sky and nearer commercialisation.
The fact is that batteries *have* improved vastly over recent time, but not possibly by quanta and in formats that excite you.
I'm rather impressed by the LiFePO4 battery that I have rigged up alongside my 2kWh of SLA gel to reduce cycling of the latter, at several times the energy density by volume and weight (and not that expensive). But I went and haggled and bought it straight off a vendor's R&D bench armed with the knowledge that it wasn't likely to turn up in consumer gear in that form, at least not for a year or two.
Remarkable amount of spittle flying in this thread...
I expect most major technical artefacts from javac to SUVs to space ships go out the door with known defects; heck I worked on a major defence project where the ship had to ship without most of its code, with the significant risk of killing innocent passers-by. And 5 days may simply not be enough time to repackage everything for a bug that's going to affect very few people. (Except possibly some loud ones with an axe to grind?)
In fact, back in C/C++ land, building mission-critical and performance-critical apps globally across many OSes and years, I don't think that I encountered ANY release of any compiler (free/commercial/whatever) that didn't have some defects requiring us to turn down optimisation generally or off for some particular files. Because getting numbers wrong is problematic for banks, even worse than getting them slowly, usually.
And BTW, every time I have tried the G1 GC for my key Java app even with the personal help of the relevant Sun/Oracle engineers, it crashes the JVM reliably. Does that mean Java is crap or even G1? Not for most users; mine turns out to be a torture test. I'll stick with CMS for now and try G1 again in a while.
Nonsense. I have Java code that I knocked out for Netscape 2 that basically still runs happily in current browsers, and is non-trivial.
And I fold that same code into a current Java application, and optimise across the old and new with Progard.
Couldn't really do that with (say) C or C++, and I've been paid shedloads to port them over the years.
The only other language that I know and use with the practical backward compatibility of Java (ie stuff more than an decade old runs perfectly surviving many OS changes/upgrades) is/bin/sh.
Slashdot Mirror
Whoosh?
I don't know. But virtual is probably divided amongst its users, eg a 1MB shared lib by ten processes is probably 100kB accounted to each, and conversely RAM may include file cache or transient anonymous areas; you'll have to RTFM I think.
Rgds
Damon
Mapping a file into memory, for example a shared library, even read-only, may show up in the 'virtual memory' usage. But it's not taking any actual memory away from anything else to do that except easily-dropped file/page cache. Sun got burnt when users claimed that Java was suddenly 'using more memory' just because they mmap() the JARs as I recall, but it makes no real difference to what's available to other apps I believe.
Rgds
Damon
Hi,
Here's the project: http://www.earth.org.uk/LiFePO4-battery-testing-with-solar-PV-off-grid-system.html
I went to see the vendor at its office because it had some interesting stuff on sale, and discussing what they were working on stumbled upon this LiFePO4 battery. It's prismatic (so compact) and has a BMS built in, suitable to accept nominal 12V solar PV directly at its inputs. (It has 4 wires; PV in and nominal 12V out, though a common +ve rather than -ve which is a slight nuisance.) BMS, ie solar charging of Li, was my big worry at the time.
Rgds
Damon
Um, you're posting in /. where precision is a good thing. You must be new here! B^> Your initial statement was palpably false and silly; your new one is fine (though I may still not agree with it).
Rgds
Damon
Getting like to compare with like is astonishingly difficult post hoc in my experience, but I did it many many years for a defence company and was able to project commodity CPU performance forward about a decade (it turned out) across families and within a single family (x86) reasonably well.
Probably few journalists have the time to embark on building such curves from scratch, though I agree that they are interesting.
Maybe do some yourself and stick them in Wikipedia?
Rgds
Damon
It works for me. Maybe it wouldn't do for you, I can't tell.
But as I actually enjoy the challenge of working with resource-constrained 'embedded' systems (my first job was designing and implementing a robotic OS and hardware 25+ years ago), this part of the fun.
Rgds
Damon
Seems unlikely. This seems to be another spittle-and-rage-filled /. thread.
Rgds
Damon
Do you have citations for any of the cases that you allude to?
Rgds
Damon
Nobody? Not ever, not one single sheet? Not like how I use almost all the paper that comes to my house for notes, or the kids to draw, etc, on *before* recycling it or using in the compost heap?
OK, clearly I must be imagining using my paper 2 or 3 times typically. And printing almost nothing out of my own.
Rgds
Damon
It's entirely fast enough for my purposes: I have front-end mirrors and CDN to serve data quickly to end users. It also handles my mail (including many thousands of SPAMs per day), and SVN and so on.
And it does mean that I've been able to run the entire system off-grid, on a few solar panels propped up against a wall! B^>
Rgds
Damon
That might even be worth it (per kWh) for some apps, such as smart phones. B^>
Unless it's 6x--8x per l or kg in which case that's be the same price per kWh as the current lot (but a lot smaller and longer-lasting) and would be *wonderful*! I could run my house for a year on a small shed's worth!
Rgds
Damon
I don't think you've been doing it right and having enough fun! I've experienced plenty of catastrophic HDD failures with little warning or possible recovery, including my last MacBook's internal HDD killed pretty abruptly by static AFAIK. (I managed to recover my SSH key, but that was about it.)
Rgds
Damon
Running a busy USENET server (I think I hovered at ~#10 in the stats for while) used to wear out normal hard drives too, back in the day; SSDs aren't especially novel in that regard IMHO. It's really only a matter of how frequent and comprehensive your backups are.
And as my USENET data didn't last longer than about a week then I think I regarded backups as largely pointless except for some very low-traffic local groups and just threw away a drive when it died and let the new one fill up again!
BTW, I've been running a server entirely on a mixture of SD cards and USB Flash for a couple of years so far, so good. I have taken efforts to reduce spurious writes but I still make sure that I have backups of critical stuff elsewhere: http://www.earth.org.uk/note-on-SheevaPlug-setup.html
Rgds
Damon
Hmm, I see a whole new slew of SPAM: "Need your anode volumetrically gifted? Feeling that your capacity is down or resistance to your action is going up, unlike you? Our new CiaLIaSi is for you!"
Rgds
Damon
I do read NS, as it happens. I even write vaguely technical stuff for money sometimes.
But spending your effort to whinge about /.'s climate being the wrong shade of purple in the latter part of an autumnal afternoon in your backyard is just a waste of everyone's effort. Just don't read TFA/TFS/TFC and spare us your peccadilloes, please.
Rgds
Damon
What fraction of the entire cell is the anode, and thus how much 'sometimes unused' space has to be left for this anode when fully turgid, and thus by what fraction does this knock down Wh/l energy density, do you think?
Anyhow, it seems as if it might be quickly commercialisable and just needs a matching top-notch cathode! B^>
Rgds
Damon
Maybe *you* only want to know about things once they are no longer R&D and are just lumpen consumer goods available in your local B&M.
Others may like to know about research, both blue-sky and nearer commercialisation.
The fact is that batteries *have* improved vastly over recent time, but not possibly by quanta and in formats that excite you.
I'm rather impressed by the LiFePO4 battery that I have rigged up alongside my 2kWh of SLA gel to reduce cycling of the latter, at several times the energy density by volume and weight (and not that expensive). But I went and haggled and bought it straight off a vendor's R&D bench armed with the knowledge that it wasn't likely to turn up in consumer gear in that form, at least not for a year or two.
Rgds
Damon
Cooling?
No, we just all believe in OverUnity, and think that an evil alliance of BigOil and AlGore is hiding the technology from us.
Hmm, tinfoil hat is feeling a bit loose.
Rgds
Damon
PS. In this house, ... oh, wait...
I am a sysadmin and have been for over 25 years, as well as a developer and consultant and architect, and I eat my own dogfood.
A Java runtime is no worse than (say) a C++ one from an admin point of view, IMHO.
Rgds
Damon
Remarkable amount of spittle flying in this thread...
I expect most major technical artefacts from javac to SUVs to space ships go out the door with known defects; heck I worked on a major defence project where the ship had to ship without most of its code, with the significant risk of killing innocent passers-by. And 5 days may simply not be enough time to repackage everything for a bug that's going to affect very few people. (Except possibly some loud ones with an axe to grind?)
In fact, back in C/C++ land, building mission-critical and performance-critical apps globally across many OSes and years, I don't think that I encountered ANY release of any compiler (free/commercial/whatever) that didn't have some defects requiring us to turn down optimisation generally or off for some particular files. Because getting numbers wrong is problematic for banks, even worse than getting them slowly, usually.
And BTW, every time I have tried the G1 GC for my key Java app even with the personal help of the relevant Sun/Oracle engineers, it crashes the JVM reliably. Does that mean Java is crap or even G1? Not for most users; mine turns out to be a torture test. I'll stick with CMS for now and try G1 again in a while.
Rgds
Damon
Nonsense. I have Java code that I knocked out for Netscape 2 that basically still runs happily in current browsers, and is non-trivial.
And I fold that same code into a current Java application, and optimise across the old and new with Progard.
Couldn't really do that with (say) C or C++, and I've been paid shedloads to port them over the years.
The only other language that I know and use with the practical backward compatibility of Java (ie stuff more than an decade old runs perfectly surviving many OS changes/upgrades) is /bin/sh.
Rgds
Damon
No, by a factor of between 5 and 10 typically. The average solar panel has an EROEI better than tar sands.
Rgds
Damon
Here you go: http://nextbigfuture.com/2011/03/deaths-per-twh-by-energy-source.html
Rgds
Damon