I think it's reasonable but I'm sure there's a lot of code down in the FS layers that would break. No one has had to deal with a non-512 byte sector disk for a while.
The SSD is a level below the file system so if it marks something as "unused" that won't really affect how long the filesystem thinks the file is.
If you write a block of zeros to it and it gives you a block of zeros back, then you still have the zeros "in" your file. If internally it just checks a flag first to see if the block is marked unused and returns all zeros if it is, you can't tell the difference.
Hmmm...I thought I had seen a real reference somewhere but I looked and all I can find are anecdotes. It *should* work that way:-). Manufacturers are not releasing much information on this internal fragmentation issue, especially the ones that have a real problem with it.
TRIM is a hack as well. It would probably be easier to just up the block size to match the native cell size but that would break a lot of existing filesystems since everybody standardized on 512 byte disk sectors ages ago.
The HD in my Macbook Pro was failing and when I was shopping for parts, I noticed that PowerbookMedic (normally I'd just go buy a hard drive locally but I needed to replace the DVD drive as well so I figured why not just get it all in one go) had an SSD available at a reasonable price so I purchased it on the theory that whatever they were shipping was a decent fit for the Mac - they didn't have any maker info on the page but I figured that the only real difference between SSDs would be max bandwidth and anything would be an improvement over a regular HD so I didn't do any research. When it arrived it was a G.Skill drive (128GB).
When I first installed it things were very zippy and I was really happy. After about a month, though, things started to slow down and I started researching and found the SSD fragmentation problem that's been referenced often. Zero'ing out the unused space on the disk did give a bit of a performance boost, but not back to the original levels. Eventually things got so bad that I removed it and replaced it with a regular HD and things got much better.
So, a few points:
1) HFS+ is not magically aligned with SSD's somehow (the Macbook Pro is running Snow Leopard so it's got the latest OS updates). You can still hit the fragmentation problem. 2) A lot of people are saying that overwriting with zero's won't do anything. Any controller will detect a block of zero's as being unused data and just mark the block as such. It's not hard to do, it's an obvious thing to do, and even the worst controller out there has a boatload of firmware in it - they are not just bare flash RAM chips hooked to the ATA bus somehow.
$1 billion is chump change in the software market. Electronics Arts makes over $4 billion a year in revenue by itself. Think about it, $1 billion/year means 1000 apps making $1 million/year. $1 million/year in revenue is a pretty small business.
This explains why the majority of apps in the App Store are things like 'iFart' or 'Mirror'. It's a very major risk to take to develop an application with no guarantee it will get by the gate keeper and then with revenues sure to be fairly small.
Well, let's talk about fixed costs and marginal costs.
There's a certain amount of fixed costs in generating an issue of Wired. That includes the writers, designers, editors, etc. All of the money that goes into generating the issue is spent before the first copy hits the App Store or the newstands.
Next, is the marginal costs per issue. Yes, an electronic copy costs less to generate than a paper copy. However, if you sell 10 iPad copies instead of 100,000 print copies, you're not going to cover your fixed costs per issue and you're going out of business.
When you print in large amounts, the costs per copy go down. You can subscribe to Wired for about a dollar per issue. I suspect that the subscription price just covers printing and postage and their profits are all made from advertising. We know that the App Store charges 30% for distributing through them. On a $5 app, that's $1.50. I'd be willing to be bet that the revenues from the newstand copy (street price is $5) isn't very far off from the electronic version.
The Web is making a major dent in newspapers and magazines because it is free and it's easily available.
iPad Apps at $5 a pop will not. When e-books and e-magazines cost 10% of the printed cost they might make some traction. As it is, I've bought books to read on my iPhone. It's not a terrible experience but it is an expensive one - the electronic versions cost as much as a paperback. I've found that if I enjoyed the electronic version, I would like to have a printed version as it's a lot easier to find in my library, browse, etc. Unfortunately with the e-prices being so high, I feel like a sucker for buying a second copy on paper. So, rather than buy an e-book I'd rather just buy the paper.
People with your attitude are the reason that the police beat people senseless for stepping out of their car for a moment. It's a border crossing, not a prison lock down. He didn't have a gun, he didn't offer violence. At worst he failed to quickly comply with an order. The appropriate punishment would have been a ticket, not a beating. The fact that the law allowed these officers to administer a beating and then press charges against him simply shows that the law is wrong.
I'm of very mixed feelings on the Constellation cancellation. On one hand, I thought that Constellation was a big loser of a program. Expendable solid rockets? Apollo style capsules? We need cheap access to space, not more aerospace contractor welfare. On the other hand, not having a manned space program sucks pretty badly too. As you said, if Obama cancelled the NASA boondoggle knowing that the Air Force had something better coming along, I would feel much better.
It doesn't need to scale up that large. The Space Shuttle has a lot of cargo bay plus capacity for up to 7 people for long on-orbit times. What we need at the moment is an Earth->Station->Earth space taxi. Double the size of the X-33 and add 24 hours of life support capacity for 2-3 passengers and you're rocking.
The key thing is to keep going. Actually launching some hardware is an amazing breakthrough given the history of developing spacecraft in the last 20 years or so for the US. Unbelievable boondoggles like the X-33 and then Constellation where hundreds of millions and billions are spent on paper spacecraft that never get built. This is absolutely fantastic.
You have to maintain the infrastructure for taking that million dollar payment. One of the difficulties in today's world is that many older works are still "under copyright" but you have no way of finding who owns them to license them, effectively taking them out of circulation.
One of the major problems with the current state of copyright is that everything is copyrighted for these ridiculous long terms. I'd like to see something like a basic 15-20 year copyright, after which you would have to re-register and maybe even pay a property tax to continue your monopoly.
My argument for regular people, then, would be "If you want to keep control, you have to show that you want control and you have to pay for it, just like real property where you can't abandon it and you have to pay property tax."
The effect of random bit flips on software is going to be hard to define. Modern hardware probably has all of the code running in RAM, not ROM as it would have been back in the 80's. A bit flip in a register could cause very odd things to happen. Perhaps someone coded a loop like:
for (i=0; i!=10; i++)
do_something();
Flip a bit in the register and that loop will not terminate until the register overflows.
I don't think you can code so that random bit flips will not be a problem. The hardware needs to be robust enough to catch them and either fix them or at least throw an error so that things can be reloaded.
I haven't looked at the communications protocols in use between the various modules but it wouldn't surprise me if there were a lot of possibilities for errors in there as well. Software engineers will put a lot of reliance on "checksums" and swear up and down that there is no possibility for things to go wrong, but in the end it turns out the checksums used are not very robust. TCP/IP checksums, for example, are almost worthless but most TCP/IP communications takes place over links with robust checksums so they're not tested very much. I implemented very simple links (TCP/IP over a VME bus - don't ask it was a whacky idea) and found that single bit errors in the hardware could get through a single layer of the checksums quite easily (that is, it would pass the IP checksums but the TCP checksums would catch things).
And so you too would have gotten taken by this scam. They received a cashier's check (aka bank cheque) and their bank accepted it. They, like you, believed that an accepted bank cheque was as good as cash so they wired the refund (which, FYI, is the same as cash, since you can't take it back) and got stuck.
So did the original - it was launched from the command prompt and the shell was used for the output of the return code. The shell is part of the base OS anyhow, and you can't boot Linux without the shell.
Shhhh...it's a little known fact that gum is considered highly dangerous (it's right up there with liquids) and so those detectors are specially tuned to detect gum wrappers. You are normally allowed only 1 stick of gum. Air marshals are also trained to monitor passengers for signs of synchronized chewing. A team of terrorists working together to chew up and mold together a gum bomb is a terrifying possibility.
Slashdot Mirror
When they can do 3D without the glasses and without giving me a headache I'll be for it. Right now the effect is mainly annoying for me.
It's a higher dollar item? iPhones go for around $400.
I think it's reasonable but I'm sure there's a lot of code down in the FS layers that would break. No one has had to deal with a non-512 byte sector disk for a while.
The SSD is a level below the file system so if it marks something as "unused" that won't really affect how long the filesystem thinks the file is.
If you write a block of zeros to it and it gives you a block of zeros back, then you still have the zeros "in" your file. If internally it just checks a flag first to see if the block is marked unused and returns all zeros if it is, you can't tell the difference.
Hmmm...I thought I had seen a real reference somewhere but I looked and all I can find are anecdotes. It *should* work that way :-). Manufacturers are not releasing much information on this internal fragmentation issue, especially the ones that have a real problem with it.
TRIM is a hack as well. It would probably be easier to just up the block size to match the native cell size but that would break a lot of existing filesystems since everybody standardized on 512 byte disk sectors ages ago.
The HD in my Macbook Pro was failing and when I was shopping for parts, I noticed that PowerbookMedic (normally I'd just go buy a hard drive locally but I needed to replace the DVD drive as well so I figured why not just get it all in one go) had an SSD available at a reasonable price so I purchased it on the theory that whatever they were shipping was a decent fit for the Mac - they didn't have any maker info on the page but I figured that the only real difference between SSDs would be max bandwidth and anything would be an improvement over a regular HD so I didn't do any research. When it arrived it was a G.Skill drive (128GB).
When I first installed it things were very zippy and I was really happy. After about a month, though, things started to slow down and I started researching and found the SSD fragmentation problem that's been referenced often. Zero'ing out the unused space on the disk did give a bit of a performance boost, but not back to the original levels. Eventually things got so bad that I removed it and replaced it with a regular HD and things got much better.
So, a few points:
1) HFS+ is not magically aligned with SSD's somehow (the Macbook Pro is running Snow Leopard so it's got the latest OS updates). You can still hit the fragmentation problem.
2) A lot of people are saying that overwriting with zero's won't do anything. Any controller will detect a block of zero's as being unused data and just mark the block as such. It's not hard to do, it's an obvious thing to do, and even the worst controller out there has a boatload of firmware in it - they are not just bare flash RAM chips hooked to the ATA bus somehow.
It's also not a hydrocarbon nor is it something you can get out of the ground.
$1 billion is chump change in the software market. Electronics Arts makes over $4 billion a year in revenue by itself. Think about it, $1 billion/year means 1000 apps making $1 million/year. $1 million/year in revenue is a pretty small business.
This explains why the majority of apps in the App Store are things like 'iFart' or 'Mirror'. It's a very major risk to take to develop an application with no guarantee it will get by the gate keeper and then with revenues sure to be fairly small.
You're supposed to say:
Please try harder to comprehend what you read.
The whip and high heels.
Well, let's talk about fixed costs and marginal costs.
There's a certain amount of fixed costs in generating an issue of Wired. That includes the writers, designers, editors, etc. All of the money that goes into generating the issue is spent before the first copy hits the App Store or the newstands.
Next, is the marginal costs per issue. Yes, an electronic copy costs less to generate than a paper copy. However, if you sell 10 iPad copies instead of 100,000 print copies, you're not going to cover your fixed costs per issue and you're going out of business.
When you print in large amounts, the costs per copy go down. You can subscribe to Wired for about a dollar per issue. I suspect that the subscription price just covers printing and postage and their profits are all made from advertising. We know that the App Store charges 30% for distributing through them. On a $5 app, that's $1.50. I'd be willing to be bet that the revenues from the newstand copy (street price is $5) isn't very far off from the electronic version.
It's not a technology - it's a price point.
The Web is making a major dent in newspapers and magazines because it is free and it's easily available.
iPad Apps at $5 a pop will not. When e-books and e-magazines cost 10% of the printed cost they might make some traction. As it is, I've bought books to read on my iPhone. It's not a terrible experience but it is an expensive one - the electronic versions cost as much as a paperback. I've found that if I enjoyed the electronic version, I would like to have a printed version as it's a lot easier to find in my library, browse, etc. Unfortunately with the e-prices being so high, I feel like a sucker for buying a second copy on paper. So, rather than buy an e-book I'd rather just buy the paper.
Hmmm...sounds like your company would be better off hiring a new systems administrator than going with Windows. Good thing you're posting as AC!
People with your attitude are the reason that the police beat people senseless for stepping out of their car for a moment. It's a border crossing, not a prison lock down. He didn't have a gun, he didn't offer violence. At worst he failed to quickly comply with an order. The appropriate punishment would have been a ticket, not a beating. The fact that the law allowed these officers to administer a beating and then press charges against him simply shows that the law is wrong.
I'm of very mixed feelings on the Constellation cancellation. On one hand, I thought that Constellation was a big loser of a program. Expendable solid rockets? Apollo style capsules? We need cheap access to space, not more aerospace contractor welfare. On the other hand, not having a manned space program sucks pretty badly too. As you said, if Obama cancelled the NASA boondoggle knowing that the Air Force had something better coming along, I would feel much better.
It doesn't need to scale up that large. The Space Shuttle has a lot of cargo bay plus capacity for up to 7 people for long on-orbit times. What we need at the moment is an Earth->Station->Earth space taxi. Double the size of the X-33 and add 24 hours of life support capacity for 2-3 passengers and you're rocking.
The key thing is to keep going. Actually launching some hardware is an amazing breakthrough given the history of developing spacecraft in the last 20 years or so for the US. Unbelievable boondoggles like the X-33 and then Constellation where hundreds of millions and billions are spent on paper spacecraft that never get built. This is absolutely fantastic.
You have to maintain the infrastructure for taking that million dollar payment. One of the difficulties in today's world is that many older works are still "under copyright" but you have no way of finding who owns them to license them, effectively taking them out of circulation.
One of the major problems with the current state of copyright is that everything is copyrighted for these ridiculous long terms. I'd like to see something like a basic 15-20 year copyright, after which you would have to re-register and maybe even pay a property tax to continue your monopoly.
My argument for regular people, then, would be "If you want to keep control, you have to show that you want control and you have to pay for it, just like real property where you can't abandon it and you have to pay property tax."
The effect of random bit flips on software is going to be hard to define. Modern hardware probably has all of the code running in RAM, not ROM as it would have been back in the 80's. A bit flip in a register could cause very odd things to happen. Perhaps someone coded a loop like:
for (i=0; i!=10; i++)
do_something();
Flip a bit in the register and that loop will not terminate until the register overflows.
I don't think you can code so that random bit flips will not be a problem. The hardware needs to be robust enough to catch them and either fix them or at least throw an error so that things can be reloaded.
I haven't looked at the communications protocols in use between the various modules but it wouldn't surprise me if there were a lot of possibilities for errors in there as well. Software engineers will put a lot of reliance on "checksums" and swear up and down that there is no possibility for things to go wrong, but in the end it turns out the checksums used are not very robust. TCP/IP checksums, for example, are almost worthless but most TCP/IP communications takes place over links with robust checksums so they're not tested very much. I implemented very simple links (TCP/IP over a VME bus - don't ask it was a whacky idea) and found that single bit errors in the hardware could get through a single layer of the checksums quite easily (that is, it would pass the IP checksums but the TCP checksums would catch things).
And so you too would have gotten taken by this scam. They received a cashier's check (aka bank cheque) and their bank accepted it. They, like you, believed that an accepted bank cheque was as good as cash so they wired the refund (which, FYI, is the same as cash, since you can't take it back) and got stuck.
Well, if you're going to run the app, you have to get to a useful state.
Linux won't boot without bash installed anyhow.
So did the original - it was launched from the command prompt and the shell was used for the output of the return code. The shell is part of the base OS anyhow, and you can't boot Linux without the shell.
45 bytes, huh? I can do it in....
#!/bin/sh
exit 42
18 bytes and it's portable across all Unices. Maybe the assembler version is faster, though?
Shhhh...it's a little known fact that gum is considered highly dangerous (it's right up there with liquids) and so those detectors are specially tuned to detect gum wrappers. You are normally allowed only 1 stick of gum. Air marshals are also trained to monitor passengers for signs of synchronized chewing. A team of terrorists working together to chew up and mold together a gum bomb is a terrifying possibility.