Your example of GPS and stereos has nothing to do with segmentation. You're just talking about companies charging for the convenience of having something pre-installed on delivery.
These are features car companies use to delineate different models in their lineup by making them 'standard' vs 'optional' features. Along with different engine sizes, paint jobs, trim, leather vs cloth seats, etc, etc. In many cases you cannot get some features without jumping up a whole model bracket (eg: often only the top model has an option for the largest engine).
The pricing tiers with Red Hat is there because not all businesses need the same thing. Businesses like to pay for only what they need.
Right. Which is exactly the same reason the different Windows versions exist. Not every customer has the same requirements.
The reason why Microsoft is being picked on for their practice of segmenting a consumer product marketed towards the general public is because the general public isn't a business.
Millions of other companies aim the same sort of market segmentation at non-businesses. Your argument is a non-sequitur.
And this is something that microsoft doesn't understand. The Mojave thing by microsoft illustrated very clearly that non-computer nerd consumers can't identify Vista. What chance is there that they'll know what to buy between the different versions of Vista/Win7? If anything else, it'll turn customers off, and they'll just stick with what they know - which just so happens to be whatever OS their computer came with.
Which is exactly how 99% of people get Windows anyway. So, what's the problem (other than "I want all the stuff Vista Ultimate has at the price of Vista Starter") ?
You've handily highlighted the biggest reason this whole argument is a farce. The only people who give a toss about all the different Vista versions are nerds arguing on Slashdot. Everyone else takes the version their machine comes with (which, like the hardware configuration, will be based on what advertisements or the salesman told them they needed), or knows enough to decide which version they want.
RHEL is only worth that much because of the requisite service agreement.
Actually, it's worth "that much" because without it our Oracle servers would be running on an unsupported platform.
Red Hat's agreement is overall cheaper than MS's equivalent agreement.
Ultimately, both of them charge amounts that are, in the grand scheme of how much it costs to operate an office, miniscule. They're certainly close enough to be comparable, and neither has a significant cost advantage over the other.
(Which suggests that Microsoft's pricing is not unreasonable.)
And "Highly Skilled Person Time".... If you've ever hired a reboot/reinstall monkey, you know those "windows admins" are a waste. When the real problems come, they simply cant solve it. And that would be a real admin, whether it be Windows, Linux, Mac, OS/360, or any other operating system.
That is utterly irrelevant to the point, which is that GPOs and AD provide you with functionality that, on Linux, you would need to hire another person or two to cover.
No Linux distro comes with anything close to the out of box functionality and ease of management provided by AD and Group Policy. It's not even in the same ballpark. Hell, it's barely playing the same game.
Except when Customers X,Y,Z has no clue what the difference is between the products and decides just not to buy and to stick with what came with their computer.
How is this different to any other product they might be buying ?
So it's in the seller's interest, and to hammer the point home you give a car analogy involving price gouging. Does this mean you agree with your parent that it's not out of a consideration of the consumers' interests it's done?
Nothing the seller of anything does is in anyone's interests except his own. His sole objective is to make as much money out of you as he can. Delivering a product you're prepared to pay for is the means to an end, not an end in itself.
The point that I'm trying to make is that there is nothing unusual, unexpected or unethical in Microsoft having a few different versions of Windows on the market. Indeed, it would be more of a surprise - and more of a reason to scrutinise their activities - if they *didn't* do it.
Just because other comapanies do it doesn't make it acceptable. They're doing the same thing, screwing you.
Everybody who sells you stuff is "screwing you". If they weren't, they wouldn't be making a profit.
There is a bigger problem with your comparison though. Most people have no idea what the difference is between the Windows versions and don't really know what they want.
That is to say, for most people it's just like every other aspect of buying a computer.
Most non-business buyers end up with Home Premium. Most business buyers end up with Business. These are typically the
Tiered support contracts are a completely different animal. Comparing the two makes no sense.
Why ? Pay more, get more. That is the principal being discussed here. How is it not comparable ?
This is "News for Nerds" right? You'll hear plenty of bitching about non-standard stereos and expensive GPS options on car forums.
The *point* is that there's nothing whatsoever unusual, unexpected, or unethical in what Microsoft is doing. Every company does it with every product they can. Childish whinging is not going to change one of the fundamental tenets of capitalism, and I sincerely doubt the inherently right-wing US culture is ever going to produce government regulations limiting corporate profit margins.
Why? Because the product being sold already has features A, B and C. In fact, as someone pointed out, there is a cost of disabling the feature, so the version with only feature A should be more expensive. So in fact you are telling your costumers - or the ones who can think anyway - they're idiots.
No more so than any other seller who practices market segmentation. For example, the car manufacturer who charges you a grand to install a GPS unit into your car when you could buy a functionally equivalent one off the shelf for 1/4 as much. Or the couple of grand they charge for a "premium stereo" that has a marginal extra component cost of maybe a few hundred.
Cost to manufacture and price at sale are only loosely related. The seller will always try to charge as much as he can, the buyer will always try to pay as little as he can.
To cap it all, free market and MS don't go very well in the same post. MS have a lot of control over what they put down their costumers throat, since they have a monopoly.
In no meaningful sense of the word, do Microsoft have a monopoly. Their only remotely directly comparable competitor on the Desktop, OS X, is priced similarly and has similar features. That suggests that their pricing structure is about right.
I am not saying this doesn't happen in other business, but it is a bad practice nonetheless.
Why ?
Person X wants feature A and is prepared to pay price P.
Person Y wants feature A and B and is prepared to pay price 1.5P.
Person Z wants feature A, B and C and is prepared to pay price 2P.
Company Q can take a single product, and with minor changes, deliver A, B and C. The company maximises their revenue and minimises their costs. The customer gets the features they want, at the price point they were prepared to pay and a perception they aren't paying for features they don't need (which cost more). Everybody is happy (or as happy as they're going to get).
It's a textbook example of capitalism and the free market, which is why it's so common.
If you even have to ask, you're in the wrong conversation.
In the Linux side of things, we can force modules not to load, only load certain hardware, not allow hardware access to any device, inbound/outbound kernel based firewall, and much others. If a user needs only a spreadsheet and inventory tracking, only allow those 2.
Great. Can you apply that policy to an appropriate selection of a few hundred machines out of a couple of thousand in a minute or so with half a dozen mouse clicks with an included and supported toolset ?
Centralised manageability in the OSS world is awesomely bad compared to the Windows world, and none of the major vendors like RHEL seem particularly interested in addressing it. There is still an overpowering and anachronistic belief that a major part of a sysadmin's job should be to assemble even the most basic toolset suitable for automatically and centrally managing his machines.
Charging is compared to what the market will bear. Windows is going against Linux in the server department. There, Linux can do 90-95% what MS can. Linux is free, licensing and all. MS has what? Easy domains, Outlook, and Sharepoint?
Comparing properly (to, for example, RHEL), the cost of Linux is not $0.
So, for the server question: how much is "Easy setup of Domains", Outlook integration, and Sharepoint licensing worth? Because Linux can handle the rest. With more work, Linux can even handle 2 of the 3 nicely (domains are still stupid in Linux). 100$? 200$?
Given that you're talking about highly-skilled person time, which tends to make capital costs pale into insignificance, you need to add a couple of zeroes onto those numbers. The ease of setup and management that things like AD and Group Policy, alone, bring to Windows are easily worth multiple full-time employees. This is before even getting into integration with other technologies like Crackberries.
I've got big issues with artifically crippled software, where all versions come on the same install media.
Completely normal behaviour in the computing world (and the business world in general).
See, for example, SANs where features like "SATA and FC intermix" are enabled by typing in some magic string of numbers, or 32-port FC switches that initially ship with only 8 ports enabled, and allow you to "scale up" by enabling ports in multiples of eight for a couple of grand a pop - again by simply typing in a license key.
If you want to be outraged about market segmentation, you'll need to be spreading yourself around a lot more companies than just Microsoft.
The RedHat systems are actually different levels of support as well as different pre-configured systems - what you are actually paying for is the support not the system (i.e. you actually get a real benefit by paying more)
Right. So you pay more and get more... just like the different versions of Windows.
Windows flavours are purely marketing and are there so some flavours can be sold more cheaply than others, they cost the same to design, build market and sell but the more complete systems can be sold for more
Given that the different versions of Windows come with different features, it's quite arguable from a conceptual point of view that they cost more (or less) to "design", depending on how you want to measure.
It's ultimately moot, however. The important point is that there's nothing unusual, special, or different whatsoever about a manufacturer targeting different price points with products that just variations on a theme. Anyone who's ever gone car shopping, will not be surprised that there are different versions of Windows with different features at different price points.
There is nothing inherently wrong with copyright. It's actually a great idea.
Why is it "moral" to give a certain class of workers the ability (and legal protection) to charge multiple times for the same piece of work ?
Why is it moral for one person to be able to control another person's new work, just because it happens to be based on their old work (ie: restrictions on "derivative works") ?
Why does a system fundamentally designed to facilitate money-making, not take any account of how much money has been made in its application ?
About the only unquestionably moral aspect of copyright is that people have a right to be properly credited for their work. Everything is debatable.
The various flavours of desktop Windows are PURELY a marketing concept and have no basis in customer needs.
Uh, market segmentation is pretty basic economics and common practice. See, for example, any car manufacturer charging $500 for a GPS unit or stereo when equivalent (if not better) models be bought off the shelf for 1/4 the price (but won't be quite as "integrated").
Heck, even Red Hat does it. They have at least 3 different licensing tiers. Any company that can do this, will do it, because they'd be stupid not to.
The idea that consumers would specially pick out Microsoft for criticism, when basically everyone does it, is laughable.
Why would anyone put up with a hopelessly-crippled-to-the-point-of-being-nearly-useless version of Windows when they could buy a bootleg of a Pro/Ultimate edition on a street corner for almost nothing or even torrent it for free?
Because most people installing Windows are OEMs, not end users.
That's right. Marketing switched "Inexpensive" for "Independent" years after the term was coined, because they couldn't convince people to buy their non-Inexpensive disks for RAID use as easily under the old meaning.
The original reason for 'inexpensive' is because collections of smaller disks in an array used to cost appreciably less than a single larger drive.
Occasionally you see this today, with brand new drives (eg: the new WD 2T drive is more than twice as much as two 1T drives), but generally it doesn't last long and the price disparity is much smaller. Used to be a RAID10 array (at least 4 drives) would cost less than a single drive of the same capacity.
Raiding is great for bandwidth... not so much for access time. Let's say someone is watching a video while you're doing some background re-encoding.
RAID (generally speaking) improves both bandwidth and access time.
You need a pretty malicious corner-case to get a worse average access time out of a RAID array than a single disk (especially if you include downtime for failures in that average;) ).
Your figures are assuming a complete copy of the drive is taken for every backup. Even in the days of drives measured in megabytes, that would be a pretty dumb way to do it.
The proper use for these mega-drives is for daily backups of smaller drives, or in raid5 with your fingers crossed.
Better to use RAID6 and avoid the cramp in your fingers.:)
Yes the OS does know about the physical location of sectors !
No, it does not. Exhibit A: bad sector remapping is completely transparent to the OS. Exhibit B: SAN LUNs that appear to the OS as a single block device may in fact be multiple levels of arrays disk different disk types and RAID levels stacked on top of each other (eg: Sun's 7000 Series that uses SSDs as an additional caching layer). Heck, even low-end SANs let you move a LUN from something like a 3-SATA-drive RAID5 to a 10-FC-drive RAID10 completely transparently to anything that might be accessing it (before, during, and after).
In the Linux kernel, the whole point of the I/O scheduler layer is to use that knowledge to optimize the movement of disk heads. For example the "elevator" scheduler attempts to move the heads from the outer cylinders, to the inner ones, and back, etc.
Linux (and other OSes) may assume that higher and lower LBA addresses equate to inner and outer areas of the "disk", but they have no way of knowing this. It has been a good 20 years since even normal consumer-level hardware started hiding the physical layout of sectors on drives from the OS (anything with an IDE or SCSI disk in it is doing this). This is why cache on the physical "disk" side is so important - because only it can know the optimal way to reorder physical disk operations.
The purpose of the IO schedulers is to account for a) different user requirements and b) different storage architectures. There is no Linux (2.6) IO scheduler called 'elevator', they are 'noop', 'deadline', 'anticipatory' and 'cfq'.
If the HDD does the same caching according to nearly the same principles, won't the data on the disk cache nearly always be a subset of the disk cached in RAM? Meaning: doesn't the disk cache have no effect whatsoever?
No, because the OS does not know about the physical layout of sectors on the disk and the HDD controller does. Therefore, it can reorder requests appropriately to maximise performance.
Disabling the cache on a hard disk gives a massive performance hit, especially for writes. They become nearly an order of magnitude slower.
In Australia, bank cards can be used the same way, but using a completely separate payment system to credit cards. Which is very annoying if you want to pay for stuff online, because you're forced to get a separate credit card. Real debit cards are almost unheard of here.
In Australia, bank-issued credit cards can almost always be linked to a savings account, so they can operate as either an "ATM card" or a credit card (note that overseas ATMs typically cannot access the linked savings account, however - VERY IMPORTANT). Obviously this requires you to have a savings account at the same bank that issued your credit card.
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Your example of GPS and stereos has nothing to do with segmentation. You're just talking about companies charging for the convenience of having something pre-installed on delivery.
These are features car companies use to delineate different models in their lineup by making them 'standard' vs 'optional' features. Along with different engine sizes, paint jobs, trim, leather vs cloth seats, etc, etc. In many cases you cannot get some features without jumping up a whole model bracket (eg: often only the top model has an option for the largest engine).
The pricing tiers with Red Hat is there because not all businesses need the same thing. Businesses like to pay for only what they need.
Right. Which is exactly the same reason the different Windows versions exist. Not every customer has the same requirements.
The reason why Microsoft is being picked on for their practice of segmenting a consumer product marketed towards the general public is because the general public isn't a business.
Millions of other companies aim the same sort of market segmentation at non-businesses. Your argument is a non-sequitur.
And this is something that microsoft doesn't understand. The Mojave thing by microsoft illustrated very clearly that non-computer nerd consumers can't identify Vista. What chance is there that they'll know what to buy between the different versions of Vista/Win7? If anything else, it'll turn customers off, and they'll just stick with what they know - which just so happens to be whatever OS their computer came with.
Which is exactly how 99% of people get Windows anyway. So, what's the problem (other than "I want all the stuff Vista Ultimate has at the price of Vista Starter") ?
You've handily highlighted the biggest reason this whole argument is a farce. The only people who give a toss about all the different Vista versions are nerds arguing on Slashdot. Everyone else takes the version their machine comes with (which, like the hardware configuration, will be based on what advertisements or the salesman told them they needed), or knows enough to decide which version they want.
RHEL is only worth that much because of the requisite service agreement.
Actually, it's worth "that much" because without it our Oracle servers would be running on an unsupported platform.
Red Hat's agreement is overall cheaper than MS's equivalent agreement.
Ultimately, both of them charge amounts that are, in the grand scheme of how much it costs to operate an office, miniscule. They're certainly close enough to be comparable, and neither has a significant cost advantage over the other.
(Which suggests that Microsoft's pricing is not unreasonable.)
And "Highly Skilled Person Time".... If you've ever hired a reboot/reinstall monkey, you know those "windows admins" are a waste. When the real problems come, they simply cant solve it. And that would be a real admin, whether it be Windows, Linux, Mac, OS/360, or any other operating system.
That is utterly irrelevant to the point, which is that GPOs and AD provide you with functionality that, on Linux, you would need to hire another person or two to cover.
No Linux distro comes with anything close to the out of box functionality and ease of management provided by AD and Group Policy. It's not even in the same ballpark. Hell, it's barely playing the same game.
Except when Customers X,Y,Z has no clue what the difference is between the products and decides just not to buy and to stick with what came with their computer.
How is this different to any other product they might be buying ?
So it's in the seller's interest, and to hammer the point home you give a car analogy involving price gouging. Does this mean you agree with your parent that it's not out of a consideration of the consumers' interests it's done?
Nothing the seller of anything does is in anyone's interests except his own. His sole objective is to make as much money out of you as he can. Delivering a product you're prepared to pay for is the means to an end, not an end in itself.
The point that I'm trying to make is that there is nothing unusual, unexpected or unethical in Microsoft having a few different versions of Windows on the market. Indeed, it would be more of a surprise - and more of a reason to scrutinise their activities - if they *didn't* do it.
Just because other comapanies do it doesn't make it acceptable. They're doing the same thing, screwing you.
Everybody who sells you stuff is "screwing you". If they weren't, they wouldn't be making a profit.
There is a bigger problem with your comparison though. Most people have no idea what the difference is between the Windows versions and don't really know what they want.
That is to say, for most people it's just like every other aspect of buying a computer.
Most non-business buyers end up with Home Premium. Most business buyers end up with Business. These are typically the
Tiered support contracts are a completely different animal. Comparing the two makes no sense.
Why ? Pay more, get more. That is the principal being discussed here. How is it not comparable ?
This is "News for Nerds" right? You'll hear plenty of bitching about non-standard stereos and expensive GPS options on car forums.
The *point* is that there's nothing whatsoever unusual, unexpected, or unethical in what Microsoft is doing. Every company does it with every product they can. Childish whinging is not going to change one of the fundamental tenets of capitalism, and I sincerely doubt the inherently right-wing US culture is ever going to produce government regulations limiting corporate profit margins.
You are assuming the price at which a product sells for is directly and proportionally related to the cost incurred creating it.
As any econ student will be happy to tell you, this assumption is wrong. Prices are set based on what the seller thinks the buyer is prepared to pay.
Why? Because the product being sold already has features A, B and C. In fact, as someone pointed out, there is a cost of disabling the feature, so the version with only feature A should be more expensive. So in fact you are telling your costumers - or the ones who can think anyway - they're idiots.
No more so than any other seller who practices market segmentation. For example, the car manufacturer who charges you a grand to install a GPS unit into your car when you could buy a functionally equivalent one off the shelf for 1/4 as much. Or the couple of grand they charge for a "premium stereo" that has a marginal extra component cost of maybe a few hundred.
Cost to manufacture and price at sale are only loosely related. The seller will always try to charge as much as he can, the buyer will always try to pay as little as he can.
To cap it all, free market and MS don't go very well in the same post. MS have a lot of control over what they put down their costumers throat, since they have a monopoly.
In no meaningful sense of the word, do Microsoft have a monopoly. Their only remotely directly comparable competitor on the Desktop, OS X, is priced similarly and has similar features. That suggests that their pricing structure is about right.
I am not saying this doesn't happen in other business, but it is a bad practice nonetheless.
Why ?
Person X wants feature A and is prepared to pay price P.
Person Y wants feature A and B and is prepared to pay price 1.5P.
Person Z wants feature A, B and C and is prepared to pay price 2P.
Company Q can take a single product, and with minor changes, deliver A, B and C. The company maximises their revenue and minimises their costs. The customer gets the features they want, at the price point they were prepared to pay and a perception they aren't paying for features they don't need (which cost more). Everybody is happy (or as happy as they're going to get).
It's a textbook example of capitalism and the free market, which is why it's so common.
Really, how powerful are GPOs?
If you even have to ask, you're in the wrong conversation.
In the Linux side of things, we can force modules not to load, only load certain hardware, not allow hardware access to any device, inbound/outbound kernel based firewall, and much others. If a user needs only a spreadsheet and inventory tracking, only allow those 2.
Great. Can you apply that policy to an appropriate selection of a few hundred machines out of a couple of thousand in a minute or so with half a dozen mouse clicks with an included and supported toolset ?
Centralised manageability in the OSS world is awesomely bad compared to the Windows world, and none of the major vendors like RHEL seem particularly interested in addressing it. There is still an overpowering and anachronistic belief that a major part of a sysadmin's job should be to assemble even the most basic toolset suitable for automatically and centrally managing his machines.
Charging is compared to what the market will bear. Windows is going against Linux in the server department. There, Linux can do 90-95% what MS can. Linux is free, licensing and all. MS has what? Easy domains, Outlook, and Sharepoint?
Comparing properly (to, for example, RHEL), the cost of Linux is not $0.
So, for the server question: how much is "Easy setup of Domains", Outlook integration, and Sharepoint licensing worth? Because Linux can handle the rest. With more work, Linux can even handle 2 of the 3 nicely (domains are still stupid in Linux). 100$? 200$?
Given that you're talking about highly-skilled person time, which tends to make capital costs pale into insignificance, you need to add a couple of zeroes onto those numbers. The ease of setup and management that things like AD and Group Policy, alone, bring to Windows are easily worth multiple full-time employees. This is before even getting into integration with other technologies like Crackberries.
I've got big issues with artifically crippled software, where all versions come on the same install media.
Completely normal behaviour in the computing world (and the business world in general).
See, for example, SANs where features like "SATA and FC intermix" are enabled by typing in some magic string of numbers, or 32-port FC switches that initially ship with only 8 ports enabled, and allow you to "scale up" by enabling ports in multiples of eight for a couple of grand a pop - again by simply typing in a license key.
If you want to be outraged about market segmentation, you'll need to be spreading yourself around a lot more companies than just Microsoft.
Considering that a Windows DVD costs maybe $0.25 to produce, I suspect that without tiered pricing people would still be able to afford it.
And the software on it ? That's written by fairies who ask nothing more than happy thoughts in payment, I suppose ?
The RedHat systems are actually different levels of support as well as different pre-configured systems - what you are actually paying for is the support not the system (i.e. you actually get a real benefit by paying more)
Right. So you pay more and get more... just like the different versions of Windows.
Windows flavours are purely marketing and are there so some flavours can be sold more cheaply than others, they cost the same to design, build market and sell but the more complete systems can be sold for more
Given that the different versions of Windows come with different features, it's quite arguable from a conceptual point of view that they cost more (or less) to "design", depending on how you want to measure.
It's ultimately moot, however. The important point is that there's nothing unusual, special, or different whatsoever about a manufacturer targeting different price points with products that just variations on a theme. Anyone who's ever gone car shopping, will not be surprised that there are different versions of Windows with different features at different price points.
Erm, that was the entire rest of his point after that sentence...
No it wasn't.
Did you even read the rest of the comment?
Yes I did.
There is nothing inherently wrong with copyright. It's actually a great idea.
Why is it "moral" to give a certain class of workers the ability (and legal protection) to charge multiple times for the same piece of work ?
Why is it moral for one person to be able to control another person's new work, just because it happens to be based on their old work (ie: restrictions on "derivative works") ?
Why does a system fundamentally designed to facilitate money-making, not take any account of how much money has been made in its application ?
About the only unquestionably moral aspect of copyright is that people have a right to be properly credited for their work. Everything is debatable.
The various flavours of desktop Windows are PURELY a marketing concept and have no basis in customer needs.
Uh, market segmentation is pretty basic economics and common practice. See, for example, any car manufacturer charging $500 for a GPS unit or stereo when equivalent (if not better) models be bought off the shelf for 1/4 the price (but won't be quite as "integrated").
Heck, even Red Hat does it. They have at least 3 different licensing tiers. Any company that can do this, will do it, because they'd be stupid not to.
The idea that consumers would specially pick out Microsoft for criticism, when basically everyone does it, is laughable.
Presumably the server based on the same kernel as Windows 7 will be Windows Server 2009 or 2010.
It will be Windows Server 2008 R2 (NT 6.1), which will be the same kernel as Windows 7.
Windows Server 2008 is the same kernel as Vista SP1 (which is why it's so funny to hear people claiming 2008 is "so much better" on the Desktop).
Windows 2003, XP SP2 (should really have been "XP R2" or "XP SE") and XP x64 were/are all basically the same under the hood.
Why would anyone put up with a hopelessly-crippled-to-the-point-of-being-nearly-useless version of Windows when they could buy a bootleg of a Pro/Ultimate edition on a street corner for almost nothing or even torrent it for free?
Because most people installing Windows are OEMs, not end users.
That's right. Marketing switched "Inexpensive" for "Independent" years after the term was coined, because they couldn't convince people to buy their non-Inexpensive disks for RAID use as easily under the old meaning.
The original reason for 'inexpensive' is because collections of smaller disks in an array used to cost appreciably less than a single larger drive.
Occasionally you see this today, with brand new drives (eg: the new WD 2T drive is more than twice as much as two 1T drives), but generally it doesn't last long and the price disparity is much smaller. Used to be a RAID10 array (at least 4 drives) would cost less than a single drive of the same capacity.
'cause SSD's don't cost $300-$500 more than their spindle counterparts, yep yep.
15k RPM drives and SSDs cost about the same on a $/GB basis, and on a $/IOP basis, SSDs absolutely wipe the floor.
Sadly, drop-in SSD replacements seem to be slow making into enterprise SANs. :(
Raiding is great for bandwidth... not so much for access time. Let's say someone is watching a video while you're doing some background re-encoding.
RAID (generally speaking) improves both bandwidth and access time.
You need a pretty malicious corner-case to get a worse average access time out of a RAID array than a single disk (especially if you include downtime for failures in that average ;) ).
Want a daily backup?
Your figures are assuming a complete copy of the drive is taken for every backup. Even in the days of drives measured in megabytes, that would be a pretty dumb way to do it.
The proper use for these mega-drives is for daily backups of smaller drives, or in raid5 with your fingers crossed.
Better to use RAID6 and avoid the cramp in your fingers. :)
Yes the OS does know about the physical location of sectors !
No, it does not. Exhibit A: bad sector remapping is completely transparent to the OS. Exhibit B: SAN LUNs that appear to the OS as a single block device may in fact be multiple levels of arrays disk different disk types and RAID levels stacked on top of each other (eg: Sun's 7000 Series that uses SSDs as an additional caching layer). Heck, even low-end SANs let you move a LUN from something like a 3-SATA-drive RAID5 to a 10-FC-drive RAID10 completely transparently to anything that might be accessing it (before, during, and after).
In the Linux kernel, the whole point of the I/O scheduler layer is to use that knowledge to optimize the movement of disk heads. For example the "elevator" scheduler attempts to move the heads from the outer cylinders, to the inner ones, and back, etc.
Linux (and other OSes) may assume that higher and lower LBA addresses equate to inner and outer areas of the "disk", but they have no way of knowing this. It has been a good 20 years since even normal consumer-level hardware started hiding the physical layout of sectors on drives from the OS (anything with an IDE or SCSI disk in it is doing this). This is why cache on the physical "disk" side is so important - because only it can know the optimal way to reorder physical disk operations.
The purpose of the IO schedulers is to account for a) different user requirements and b) different storage architectures. There is no Linux (2.6) IO scheduler called 'elevator', they are 'noop', 'deadline', 'anticipatory' and 'cfq'.
If the HDD does the same caching according to nearly the same principles, won't the data on the disk cache nearly always be a subset of the disk cached in RAM? Meaning: doesn't the disk cache have no effect whatsoever?
No, because the OS does not know about the physical layout of sectors on the disk and the HDD controller does. Therefore, it can reorder requests appropriately to maximise performance.
Disabling the cache on a hard disk gives a massive performance hit, especially for writes. They become nearly an order of magnitude slower.
In Australia, bank cards can be used the same way, but using a completely separate payment system to credit cards. Which is very annoying if you want to pay for stuff online, because you're forced to get a separate credit card. Real debit cards are almost unheard of here.
In Australia, bank-issued credit cards can almost always be linked to a savings account, so they can operate as either an "ATM card" or a credit card (note that overseas ATMs typically cannot access the linked savings account, however - VERY IMPORTANT). Obviously this requires you to have a savings account at the same bank that issued your credit card.