Questions asked while teaching Windows Vista and Computer Hardware courses



  • I was a part-time instructor at a local community college for three years. I enjoyed teaching but my current job no longer affords me the time to do it.

    My students were a mix of traditional freshman/sophomores and non-traditional students, including adults looking for a refresher course on technology, those retraining for technology jobs, and those who knew what the power button is but nothing else. 

    These are some questions brought up during class. I know these aren't true "WTFs" but I thought we could all use a little laugh.

    • "Does a hardrive weigh more when it gets formatted?"
    • (On VMWare, which we used to run the VMs of Vista for the class) "My DVD player thingy is locked up. How do I eject Vista?"
    • "Does using RAID like, keep bugs away or something?" (I kid you not)
    • (Question regarding an external hard drive, which was required for the Vista course to store VMWare machines) "I don't have a hard drive...can I just use these {spindle of CD-Rs} instead?"
    • (Not a question, but humorous anyhow. Again, VMWare is involved.) Student A to Student B: "No, you're on the wrong Vista. You are on the host machine. You need to do that on the parasite machine."

    I have some more written down somewhere but I think these were among the best.



  • @citking said:

    "Does a hardrive weigh more when it gets formatted?"
     

    I've had that question and it led into an interesting discussion of metaphysics.

     



  • @citking said:

    "Does using RAID like, keep bugs away or something?" (I kid you not)
    Before, while or after you explained what RAID was?



    When I took courses for system administration there was one guy who just couldn't understand why all of the 4GB of RAM wouldn't show up on a 32-bit XP install (despite being explained this multiple times).



    Then there's shitty applications that are so enterprisey they're actually like 8 seperate user-end programs and are so shitty they don't even inform the users which application they're using so HD gets calls like "Peoplesoft broke" "which application?" "Peoplesoft" "General-ledger, Accounting... which application?" "Peoplesoft, why the fuck can't you people just help me with Peoplesoft?" "because there's 8 Peoplesoft applications and 7 more [something I forgot the name of] applications that are replacing them but get called Peoplesoft as well and each one has its own application admin team and we don't have any tools to deal with any 'Peoplesoft' issue." "Oh... well X helped me last time" "Accounts Recievable it is then".



  • @Lingerance said:

    one guy who just couldn't understand why all of the 4GB of RAM wouldn't show up on a 32-bit XP install
     

    I've never heard a proper explanation for that one either, beyond "32 bit can't allocate all that RAM" despite 2^32 being precisely enough to address every byte in 4GB. Also tons of noise when doing a little googlin' on the subject, so that's not helping either.



  • @dhromed said:

    I've never heard a proper explanation for that one either, beyond "32 bit can't allocate all that RAM" despite 2^32 being precisely enough to address every byte in 4GB. Also tons of noise when doing a little googlin' on the subject, so that's not helping either.
     

    Windows uses some of the memory space for DMA things like accelerated graphics or talking with hardware.  This is why there isn't an exact number as to how much memory is available: it could be anywhere between 2.5GB and 3.75GB depending on BIOS settings and installed hardware.

    DOS had a similar restriction: there was 1MB addressable (20 bits) in the early Intel CPUs - but only 640KB available to DOS. The 384KB between 640KB and 1024KB was used for graphics and extended/expanded memory pages. Later CPUs could use other memory for that use so some of the "upper memory" became available for device drivers (TSRs).



  • It is rather simple, the top 2 GB of virtual memory is reserved for the system. (top 1 GB if specifically compiled).

    In physical memory, some addresses are used for memory mapped IO devices, like the harddrive and what not.



  • @Zemm said:

    Windows uses some of the memory space for DMA
    things like accelerated graphics or talking with hardware.  This is why
    there isn't an exact number as to how much memory is available: it could
    be anywhere between 2.5GB and 3.75GB depending on BIOS settings and
    installed hardware.
     

    But if I have 1GB installed, XP
    reports 1GB just fine, and it will use that extra memory space all the
    same. So it makes no sense that XP doesn't report the full 4GB.




  • @dhromed said:

    But if I have 1GB installed, XP
    reports 1GB just fine, and it will use that extra memory space all the
    same. So it makes no sense that XP doesn't report the full 4GB.
     

    There's 4GB of addressable space with 32 bits. Windows needs "some", let's say 512MB, for DMA and hardware devices - things need a block of memory addresses meaning that you can't use those blocks for general memory. That means there's only 3.5GB left as "RAM". If you only have 1GB installed then it can see the entire 1GB, since it can organise its memory mapping so that the devices are in the "top" part of the address space.

    I think 32 bit Windows 7 actually reports something like "4GB installed, 3.5GB available" in its system properties, so I guess the "misreporting" is fixed...

     



  • @Zemm said:

    If you only have 1GB installed then it can see the entire 1GB, since it can organise its memory mapping so that the devices are in the "top" part of the address space.
     

    But... that top part doesn't exist. I only have the one GB.

    Those top mappings refer to the page file, then?

     

     



  • @dhromed said:

    @Zemm said:

    If you only have 1GB installed then it can see the entire 1GB, since it can organise its memory mapping so that the devices are in the "top" part of the address space.
     

    But... that top part doesn't exist. I only have the one GB.

     

     

    Is this one of them troll posts i read about?



  • @dhromed said:

    @Zemm said:

    Windows uses some of the memory space for DMA things like accelerated graphics or talking with hardware.  This is why there isn't an exact number as to how much memory is available: it could be anywhere between 2.5GB and 3.75GB depending on BIOS settings and installed hardware.
     

    But if I have 1GB installed, XP reports 1GB just fine, and it will use that extra memory space all the same. So it makes no sense that XP doesn't report the full 4GB.


    Seems that XP's physical memory limit is 4GB. My guess would be that the problem is accounting.



  • @dhromed said:

    @Zemm said:

    If you only have 1GB installed then it can see the entire 1GB, since it can organise its memory mapping so that the devices are in the "top" part of the address space.
     

    But... that top part doesn't exist. I only have the one GB.

    Those top mappings refer to the page file, then?

     

     

    4GB of accessible memory (void* size 4 bytes) which will include your video memory, other device flash memory and the remaining part goes to your main memory.



  • @dhromed said:

    But... that top part doesn't exist. I only have the one GB.

    Those top mappings refer to the page file, then?

     

    Assuming you aren't trolling and are genuinely curious, here's my attempt at explaining (and this is simplified somewhat):

    The OS always has an address space of 4GB worth of memory locations. Memory locations are used for TWO things essentially, the primary one being the actual physical memory chips installed on your motherboard, the second thing being memory addresses in your hardware (like your video card); this being called DMA (Direct Memory Access).

    The reason DMA is done is to provide a fast and direct way for the CPU to write information to and from the device, so instead of the CPU having to perform an I/O instruction to send pixels to the video device, it can just write to a specific memory location, which the video card intercepts and puts on the screen.

    So, 32 bit XP ALWAYS has a total of 4GB of memory "space" for it to use, regardless of how much physical memory is installed. This is simplifying a bit, but the actual memory chips end up at the bottom of this space, and the DMA hardware ends up at the top of this space. So if you have 2GB of physical memory installed into your machine,  the bottom 2GB of the memory address space will be assigned to this physical memory, and a little bit at the top of the 4GB of space will be used for the DMA devices (typically around 500MB is used for DMA type stuff). 

    So you have this 4GB of available addresses, which can be used for one of two things, actual physical memory, or DMA. You NEED to have the DMA address space for your computer to work at any efficient speed at all (or else we'd be back to the goode olde days where everything was slow), so you always have this ~500MB chunk of used addresses at the top of the space. If you install 4GB of actual physical memory, now you have a problem, because you're trying to fill 4GB worth of possible addresses with 4.5GB of stuff. Unfortunately because you need the DMA address space, you "lose" some of your physical memory. 

    Obviously if you haven't used all of your 4GB of available addresses, you're going to have "unused" addresses at which there is neither physical memory or a DMA device. 



  • @XIU said:

    which will include your video memory, other device flash memory and the remaining part goes to your main memory.

    Man, it's like a broken record.

    1GB is fully reported and (apparently) fully used for user programs. Where does shared video memory + device flash mem + whatever go when I have only 1GB?



  • @EJ_ said:

    Assuming you aren't trolling and are genuinely curious
     

    I'm curious why my questions are considered ridiculous when this information is nowhere to be found, or, probably more accurately, lost in the incredible noise of confused people on idiot forums.

    In fact, I had never even seen any reference to DMA anywhere regarding this subject. You're the first one to bring it up, which is quite a leap.

    @EJ_ said:

    stuff

    Finally. You're the first one to actually resolve the conundrum of an OS using addresses for memory that does not exist as sticks of RAM. Thanks for that.

     

    Just so I got this straight, my video card, with 1GB of RAM, will have its memory addressed by Windows, chipping off a GB of my 4GB?



  • Here's some awesome paint.exe pictures I drew to help illustrate:

    You have 4GB of address space total to use for "whatever". In this example you have a 2GB memory stick installed and ~500MB for the IO stuff (DMA, other acronyms):

    2gb

     Here is what it looks like with a 4GB memory stick installed:

    4gb

    You can see that were it not for this IO Space requirement, all 4GB of your physical installed memory would be addressable, but alas, you only have 4GB of addresses that the CPU can give out, and 4.5GB of things wanting those addresses, so somebody doesn't get an address.

    I think what trips people up is confusing "physical memory installed" with "addressable memory space". They're separate entities.

    Using a 64-bit cpu and OS (or using other memory trickery) doesn't technically "solve" this problem, it just makes your total addressable space much, much larger. Some day we'll run up against the 64 bit wall, and there'll be holo-forum posts with people asking "why aren't all 16 exabytes of memory being recognized??"



  • @dhromed said:

    I'm curious why my questions are considered ridiculous when this information is nowhere to be found, or, probably more accurately, lost in the incredible noise of confused people on idiot forums.

    I'm with you, man. I didn't know any of this and I was thinking the same thing you asked until I finished this thread. I don't know why people considered the questions ridiculous.



  • Back in the old days, we had lots of ways of tricking cpu's into accessing ram beyond the normally addressable ranges -- bank switching and what not.



  • @Medezark said:

    Back in the old days, we had lots of ways of tricking cpu's into accessing ram beyond the normally addressable ranges -- bank switching and what not.

     

    A boot disk with a modified autoexec.bat to read extended memory so I could play DOOM.



  • @EJ_ said:

    Here's some awesome paint.exe pictures I drew to help illustrate:
     

    My special powers of abstract visualisation are strong enough to get the idea, but thanks for the effort. :)



  • @Medezark said:

    Back in the old days, we had lots of ways of tricking cpu's into accessing ram beyond the normally addressable ranges -- bank switching and what not.

    32-bit Windows has PAE, if your motherboard can cope with it. And your drivers won't crash with it enabled.

    Like anything in the Windows ecosystem, it's a problem Microsoft solved decades ago, but they can't deploy the solution because there's too much incompatible third-party "stuff" out there. Oh well, gets people moving to 64-bit quicker, so that's a good thing.



  • @citking said:

    parasite machine

    Made my day.

     

    @blakeyrat said:

    32-bit Windows has PAE, if your motherboard can cope with it. And your drivers won't crash with it enabled.

    Well, PAE is a hack that gets you back to the horror that was segmented addressing, anyways.

    It's probably better to stay away from it as you're more or less bound to run into crappy drivers.



  • @Lingerance said:

    @citking said:
    "Does using RAID like, keep bugs away or something?" (I kid you not)
    Before, while or after you explained what RAID was?
     

    Before, like right after I wrote it on the board. The student was obviously making a joke but for a second there I wasn't so sure....



  •  Is it just me, or is it a bit much to expect basic computer literacy students to grasp VMWare and RAID? VMWare in particular - christ, if you don't know anything but the power button, how the hell are you going to get virtualization?

    The RAID thing - well, you could see it, honestly. If the guy thinks in terms of software, and knows that software has 'bugs and viruses' - which are 'bad things computers get', and is true enough... That, plus the fact that a lot of software has anthropomorphic names based on what it does, it's not entirely unreasonable to surmise that RAID is a software package that 'keeps away bugs'. It's easy to laugh when you know, but in an absense of any knowledge but pop culture computer stuff, what are you going to understand? Computers run software, software can have bugs and viruses, and software has various impressive names.

    And again, as far as the hard drive thing goes... well, the hard drive is an external device that stores data. It's a different form factor than a CD, but so's a memory stick, which provides the same basic functionality. And it also holds data and can be rewritten. Technically, you could use a CDR if you stored the data temporarily on the host machine's drive, though it would be a PITA with limited lifespan.

    Most of these questions aren't stupid, they're just extrapolations based on limited data - by people who came to learn specifically because they lack that data. My 2-year-old does the same thing, except about basic things with the entire world, not just computers... it takes a while to realize you have to take him seriously and get that he's using all the information he has to judge about the situation. Example: He was in the car and saw a zebra on a u-haul truck, and said, "Horse!". Looking around and not seeing the u-haul, I said I didn't think there was a horse, and he replied, tentatively, "Cow?". So, I look around again, and there's the zebra. On the face of it, thinking that a horse is a cow is absurd - but he saw something, and when told it wasn't a horse, made the next best guess: Big animal with a big nose that's black and white and lives on a farm, but not a horse? A cow is pretty much the best option, even though this one had stripes instead of spots.

    So, yeah, these extrapolations are absurd, but when you look at it from the perspective of someone who doesn't have any baseline, they're not stupid.



  • @dhromed said:

    [T]his information is nowhere to be found, or, probably more accurately, lost in the incredible noise of confused people on idiot forums.
     

    http://en.wikipedia.org/wiki/Virtual_memory

    might provide a starting point for further reading.



  • @EJ_ said:

    Here's some awesome paint.exe pictures I drew to help illustrate:

    You have 4GB of address space total to use for "whatever". In this example you have a 2GB memory stick installed and ~500MB for the IO stuff (DMA, other acronyms):

    2gb

     Here is what it looks like with a 4GB memory stick installed:

    4gb

    You can see that were it not for this IO Space requirement, all 4GB of your physical installed memory would be addressable, but alas, you only have 4GB of addresses that the CPU can give out, and 4.5GB of things wanting those addresses, so somebody doesn't get an address.

    I think what trips people up is confusing "physical memory installed" with "addressable memory space". They're separate entities.

    Using a 64-bit cpu and OS (or using other memory trickery) doesn't technically "solve" this problem, it just makes your total addressable space much, much larger. Some day we'll run up against the 64 bit wall, and there'll be holo-forum posts with people asking "why aren't all 16 exabytes of memory being recognized??"

     

     

    Hey, wanna buy my PC? it has Win XP (not the unsupported 64bit one) 4gb ram and 4x1gb graphics cards ? it is sooo quick



  • @blakeyrat said:

    @Medezark said:

    Back in the old days, we had lots of ways of tricking cpu's into accessing ram beyond the normally addressable ranges -- bank switching and what not.

    32-bit Windows has PAE, if your motherboard can cope with it. And your drivers won't crash with it enabled.

    Like anything in the Windows ecosystem, it's a problem Microsoft solved decades ago, but they can't deploy the solution because there's too much incompatible third-party "stuff" out there. Oh well, gets people moving to 64-bit quicker, so that's a good thing.

    The same thing holding people back from PAE is also holding them back from 64-bit operating systems.  I don't mind 64-bit Windows 7 too much because half of the crap that doesn't work on 64-bit doesn't work on 7 anyways.  But, 64-bit XP was hell because nothing supported it.  Besides, 64-bit XP wasn't the 64-bit version of Windows XP, it was the workstation version of 64-bit Windows Server 2003.

    I currently dual boot Windows 7 32-bit and 64-bit, hoping to eventually make a full transition to 64-bit.  I find myself in 32-bit about 90% of the time.  The biggest culprit is iPhone drivers.  There are 64-bit iPhone drivers, but they are way flakyer than the 32-bit ones.



  • @PeriSoft said:

    The RAID thing - well, you could see it, honestly. If the guy thinks in terms of software, and knows that software has 'bugs and viruses' - which are 'bad things computers get', and is true enough... That, plus the fact that a lot of software has anthropomorphic names based on what it does, it's not entirely unreasonable to surmise that RAID is a software package that 'keeps away bugs'. It's easy to laugh when you know, but in an absense of any knowledge but pop culture computer stuff, what are you going to understand? Computers run software, software can have bugs and viruses, and software has various impressive names.

     

    Well, sure, but this assumes someone so wet behind the ears that he's never wondered why:

    • you buy books from a South American tribe of female warriors
    • job postings are managed by a big scary creature that hides under your bed
    • shiny metal plating, people singing in foreign languages, and jungle expeditions somehow let you surf the web
    • a medieval king of Denmark connects your earpiece to your phone
     

     



  • @EJ_ said:

    The OS always has an address space of 4GB worth of memory locations. Memory locations are used for TWO things essentially, the primary one being the actual physical memory chips installed on your motherboard, the second thing being memory addresses in your hardware (like your video card); this being called DMA (Direct Memory Access).

    The reason DMA is done is to provide a fast and direct way for the CPU to write information to and from the device, so instead of the CPU having to perform an I/O instruction to send pixels to the video device, it can just write to a specific memory location, which the video card intercepts and puts on the screen.

    So, 32 bit XP ALWAYS has a total of 4GB of memory "space" for it to use, regardless of how much physical memory is installed. This is simplifying a bit, but the actual memory chips end up at the bottom of this space, and the DMA hardware ends up at the top of this space. So if you have 2GB of physical memory installed into your machine,  the bottom 2GB of the memory address space will be assigned to this physical memory, and a little bit at the top of the 4GB of space will be used for the DMA devices (typically around 500MB is used for DMA type stuff). 

    Let's clear all the misconceptions.

    All modern processors support PAE, which with introduction of x64 architecture was extended to support even larger memory. First version of PAE supported 36 bit, but now at least 40 bit physical address is supported.

    PCI devices are mapped below 4GB. Because not all PCI cards support 64 bit addressing. For that reason, some amount of RAM below 4 GB may be remapped by the chipset. For example, if you have 4 GB, 1GB from 0xC0000000 to 0xFFFFFFFF will be remapped to 0x100000000-140000000. So you get 5GB of physical address space. Note that it does not have anything to do with DMA. Don't confuse DMA with memory-mapped PCI devices.

    32-bit Windows supports PAE and can support memory over 4GB. But client SKUs are artificially limited to support only 4GB of physicall address. Thanks to lazy programmers and half-assed devices that can't or don't suport proper PHYSICAL_ADDRESS type. Server SKU (Windows Server 2003) x86 flavor doesn't have that limitation.

     



  • @Helix said:

    Hey, wanna buy my PC? it has Win XP (not the unsupported 64bit one) 4gb ram and 4x1gb graphics cards ? it is sooo quick

    Grr.. GRAPHICS MEMORY DOES NOT WORK LIKE THAT. It is not mapped in it's entirety into the system address space, instead, a movable "aperture" of graphics memory (usually only about 128MB) of graphics memory is mapped into the I/O region of the system address space.



  • There we go. This is the kind of information-dense discourse I prefer to see on my interwebs. The SNR approaches sys' car's MPG downhill. I can only hope Google and Bing agree and index this thread really high for searches on Windows XP 32 bit allocates 3.5 GB RAM can't allocate 4 GB RAM limited 64 bit see all 4 GB.

    Aye.



  • @Jaime said:

    The same thing holding people back from PAE is also holding them back from 64-bit operating systems.  I don't mind 64-bit Windows 7 too much because half of the crap that doesn't work on 64-bit doesn't work on 7 anyways.  But, 64-bit XP was hell because nothing supported it.  Besides, 64-bit XP wasn't the 64-bit version of Windows XP, it was the workstation version of 64-bit Windows Server 2003.

    I currently dual boot Windows 7 32-bit and 64-bit, hoping to eventually make a full transition to 64-bit.  I find myself in 32-bit about 90% of the time.  The biggest culprit is iPhone drivers.  There are 64-bit iPhone drivers, but they are way flakyer than the 32-bit ones.

    I must admit personally I only run 64bit these days and I find most of the stuff I need runs just fine (VS, Office, Steam etc), I have a Nokia phone rather than an iPhone and as rubbish as the latest Ovi stuff is it works fine (or seems to anyway - I have two bluetooth devices that have no drivers loaded but bluetooth seems to work anyway - go figure).

     

     



  • @alegr said:

    allthewords

     

    You're right about the DMA, picked the wrong acronym, I was confusing memory mapped IO with DMA in my head. All I meant to get across was that "Addressable space" is different than "physically installed memory", and "Addressable space" has a limit that may be less than "physically installed memory" + "memory mapped IO" so the physically installed memory gets the shit end of the stick.

    Wasn't trying to get into the specifics :) but I did go down the wrong acronym path. Was attempting to simplify the situation to explain in a general way rather than using specifics, which was what seemed to compound the original confusion. 

    And yes, there are other methods that OSs can use (in general) to get around addressing limitations, such as PAE, or just increasing the address space (64 bit).



  • @da Doctah said:

    • shiny metal plating, people singing in foreign languages, and jungle expeditions somehow let you surf the web

     

     

    Really? You passed up a perfectly good opportunity to say "small combusting canids"?



  • @Tyler said:

    Really? You passed up a perfectly good opportunity to say "small combusting canids"?

    You mean psychic Russian fighter jets, right?



  • @PeriSoft said:

    So, yeah, these extrapolations are absurd, but when you look at it from the perspective of someone who doesn't have any baseline, they're not stupid.



    The point is to teach them, which is what I did. Nowhere did I say they were stupid questions. In fact, my tag on the OP says otherwise. I just brought up moments that were funny to bring a little sunshine to peoples' lives.You must have come up with the stupid part yourself somewhere.

    @PeriSoft said:

    And again, as far as the hard drive thing goes... well, the hard drive
    is an external device that stores data. It's a different form factor
    than a CD, but so's a memory stick, which provides the same basic
    functionality. And it also holds data and can be rewritten. Technically,
    you could use a CDR if you stored the data temporarily on the host machine's drive, though it would be a PITA with limited lifespan.


    And no, there is absolutely no way you would use CDRs to store virtual machines. The lag time would be horrendous and you'd need a spindle of them to store the drives (depending, of course, how much disk space you allocate and whether or not it is allocated up-front or not). Lastly, an external hard drive is in no way comparable to a spindle of CDRs. THat's like saying that a monitor is the same thing as a printer since they belong to the same class of device.



  •  @blakeyrat said:

    @Tyler said:
    Really? You passed up a perfectly good opportunity to say "small combusting canids"?

    You mean psychic Russian fighter jets, right?

     I'm not sure I've ever browsed the web using ClairvoyantMig, but I'll have to give it a try.



  • @Tyler said:

    @da Doctah said:

    • shiny metal plating, people singing in foreign languages, and jungle expeditions somehow let you surf the web

     

     

    Really? You passed up a perfectly good opportunity to say "small combusting canids"?

     

    Are you by any chance referring to "dyslexic backwoods craft and survival handbooks"?



  • @EJ_ said:

    <Memory mapping explanation>
    I can't find the upvote button. Stupid Community Server...



  •  One way to think about it is to say that CPUs are like internal combustion engines. They may differ in how the bits fit together, how many bits there are or even how quickly they do their jobs. But, basically, they're all pretty much alike: fuel comes in, combustion happens, piston moves, and wheels turn.

    Word size can be likened to the amount of travel the gas pedal has; more gas means more fuel is combusted (work is done) every cycle. Also, relevant to the above discussion, larger word size means more pistons per revolution are available.



  • @Helix said:

     One way to think about it is to say that CPUs are like internal combustion engines. They may differ in how the bits fit together, how many bits there are or even how quickly they do their jobs. But, basically, they're all pretty much alike: fuel comes in, combustion happens, piston moves, and wheels turn.

    Word size can be likened to the amount of travel the gas pedal has; more gas means more fuel is combusted (work is done) every cycle. Also, relevant to the above discussion, larger word size means more pistons per revolution are available.

    Who and what are you replying to?

    So like the massive diesels in a cruise ship are, what, some IBM big-iron? And something like a bus engine would be like my desktop computer, and then my laptop is a Toyota Echo? And my cellphone is a Vespa, and my thermostat is like a string trimmer!



  • @blakeyrat said:

    @Helix said:

     One way to think about it is to say that CPUs are like internal combustion engines. They may differ in how the bits fit together, how many bits there are or even how quickly they do their jobs. But, basically, they're all pretty much alike: fuel comes in, combustion happens, piston moves, and wheels turn.

    Word size can be likened to the amount of travel the gas pedal has; more gas means more fuel is combusted (work is done) every cycle. Also, relevant to the above discussion, larger word size means more pistons per revolution are available.

    Who and what are you replying to?

    So like the massive diesels in a cruise ship are, what, some IBM big-iron? And something like a bus engine would be like my desktop computer, and then my laptop is a Toyota Echo? And my cellphone is a Vespa, and my thermostat is like a string trimmer!

     

    Yes, exactly except for the bus has a trailer attachment which is PAE, and that you can't ride on a string trimmer so therefore should not have a user interface.



  •  This analogy is getting away from us fast.



  • @dhromed said:

     This analogy is getting away from us fast.

     

    i blame the tesla roaster



  • @havokk said:

    @citking said:

    "Does a hardrive weigh more when it gets formatted?"
     

    I've had that question and it led into an interesting discussion of metaphysics.

     

    A formated dist with every bit set to 0 has all its magnetic poles aligned. To make this alignment, you have to apply energy. Over time, the hard drive will gradually loose it magnetization until its all "white noise": the entropy increases. In this process, the drive will release its potential magnetic energy in the form of heat. Therefore, formating adds a bit of potential energy to the drive and as every energy field carries a certain amount of mass (E=mc2), a formated disk has more mass than a random disk.

    That said, a formated drive that previously contained the complete works of Shakespeare may have lost mass...



  • @Helix said:

    @dhromed said:

     This analogy is getting away from us fast.

     

    i blame the tesla roaster

     Now I want to cook dinner using a tesla coil.

     

     



  • @Lingerance said:

    Then there's shitty applications that are so enterprisey they're actually like 8 seperate user-end programs and are so shitty they don't even inform the users which application they're using so HD gets calls like "Peoplesoft broke" "which application?" "Peoplesoft" "General-ledger, Accounting... which application?" "Peoplesoft, why the fuck can't you people just help me with Peoplesoft?" "because there's 8 Peoplesoft applications and 7 more [something I forgot the name of] applications that are replacing them but get called Peoplesoft as well and each one has its own application admin team and we don't have any tools to deal with any 'Peoplesoft' issue." "Oh... well X helped me last time" "Accounts Recievable it is then".
     

    Our HR department has been bragging about the fact that they just replaced Peoplesoft with Oracle...



  • @kilroo said:

    @Helix said:

    @dhromed said:

     This analogy is getting away from us fast.

     

    i blame the tesla roaster

     Now I want to cook dinner using a tesla coil.

     

     

    You mean Tesla helix?


  • @JvdL said:

    A formated dist with every bit set to 0 has all its magnetic poles aligned. To make this alignment, you have to apply energy. Over time, the hard drive will gradually loose it magnetization until its all "white noise": the entropy increases. In this process, the drive will release its potential magnetic energy in the form of heat. Therefore, formating adds a bit of potential energy to the drive and as every energy field carries a certain amount of mass (E=mc2), a formated disk has more mass than a random disk.

    That said, a formated drive that previously contained the complete works of Shakespeare may have lost mass...

    With modern recording methods, no matter what's actual information written, the magnetization pattern is posessing noise-like properties. The more uniform spectrum, the better; it allows for better BER. If you just fill the drive with zeros, the magnetization won't be less random. Because there is also scrambling.

    A completely blank platter, just after magnetic layer deposition, has domains randomly magnetised. There is no such thing as non-magnetised domain. If you remagnetize it in different direction, its energy doesn't change.



  • @JvdL said:

    To make this alignment, you have to apply energy.

    Incorrect, you apply a magnetic field - this is not the same as directly adding energy. There is no guarantee that a one state in the disk requires more energy to occupy than a zero state.

    @JvdL said:

    Over time, the hard drive will gradually loose it magnetization until its all "white noise": the entropy increases.

    I don't have enough understanding of solid state physics to make a difinitive comment on this, but you cannot not necessarily associate an entropy increase with demagnetization.

    @JvdL said:

    In this process, the drive will release its potential magnetic energy in the form of heat.

    No, it won't; magnetism is nothing like electric charge, so unless you've figured out how to difinitively prove the existence of magnetic monopoles AND that they exist within our galaxy I really think you are off base here. I think you've also misunderstood the processes by which heat transfer occurs.

    @JvdL said:

    Therefore, formating adds a bit of potential energy

    Possibly, but not necessarily (and certainly not from your previous arguments), see first comment.

    @JvdL said:

    every energy field carries a certain amount of mass

    What? Who taught you Physics? "Fields" describe directionality in energy - they have no mass.

    @JvdL said:

    (E=mc2)

    Not a field description; this has magnitude but no direction.

    @JvdL said:

    a formated disk has more mass than a random disk.

    Possibly, but you have not prooven this with your above argument. It has more entropy, but that's not the same as mass. 1,000 straws dumped out of a container have more entropy than all lined up neatly end to end, but they don't have any more mass.

     

    Edit: Fields describe directionality, but not necessarily in energy.


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