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Do HDDs get slower as they get full?

I know that SSDs work this way and I know why they do, but do HDDs work the same way, or can I increase my HDD capacity to 99% without seeing any performance drop?

Also, I know that with an SSD if you keep it 90%+ full it will reduce drive longevity. Is this also true for HDDs?
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  1. HDD performance doesn't drop off like SSD's as they fill up.

    Performance various across the disk from inner to outer edge, with inner giving best performance, which is what the disk defragmenter handles.

    As for ageing, as it's a mechanical spinning drive, the motors do wear, as do the read arms and so does the actual surface.

    I think a consumer drive hitting 5 years is good, here at work we have some way past that and being on 24/7, does keep them alive longer.
  2. If the free space gets too low on the OS partition it will slow Windows down because there will be less space available for the swap file (virtual memory).
  3. You can fill your HDD with data, they age differently. Read these:
    Reading and writing data: http://www.explainthatstuff.com/harddrive.html
    Slowing caused by failure: https://www.howtogeek.com/173463/bad-sectors-explained-why-hard-drives-get-bad-sectors-and-what-you-can-do-about-it/
  4. HDD will not age faster with full HDD, but will perform much slower with full disc.
    Each time you do write you need to scan more space to find free area and sometimes you need to move stuff around to make bigger write operation.
  5. Rdslw said:
    HDD will not age faster with full HDD, but will perform much slower with full disc.
    Each time you do write you need to scan more space to find free area and sometimes you need to move stuff around to make bigger write operation.

    Fragmentation may be a problem but the File Allocation Table keeps track of the disk space, to it is not actual scanning, it is just the reader head jumping from one position to another.
  6. das_stig said:
    HDD performance doesn't drop off like SSD's as they fill up.

    Performance various across the disk from inner to outer edge, with inner giving best performance, which is what the disk defragmenter handles.

    As for ageing, as it's a mechanical spinning drive, the motors do wear, as do the read arms and so does the actual surface.

    I think a consumer drive hitting 5 years is good, here at work we have some way past that and being on 24/7, does keep them alive longer.


    That last line, if I'm reading this correctly...Are you saying if I keep my HDDs running 24/7 may also increase longevity? Or did I read that incorrectly? Because I would assume the opposite is true based off of the 2nd to last line. Keeping them running 24/7 (at least I thought) causes the moving parts to degrade more quickly.
  7. testtube5 said:
    das_stig said:
    HDD performance doesn't drop off like SSD's as they fill up.

    Performance various across the disk from inner to outer edge, with inner giving best performance, which is what the disk defragmenter handles.

    As for ageing, as it's a mechanical spinning drive, the motors do wear, as do the read arms and so does the actual surface.

    I think a consumer drive hitting 5 years is good, here at work we have some way past that and being on 24/7, does keep them alive longer.


    That last line, if I'm reading this correctly...Are you saying if I keep my HDDs running 24/7 may also increase longevity? Or did I read that incorrectly? Because I would assume the opposite is true based off of the 2nd to last line. Keeping them running 24/7 (at least I thought) causes the moving parts to degrade more quickly.


    Depends on the drive and how it was engineered to run. Desktop-grade drives like our BarraCuda are spec'ed for 8 hours a day x 5 days a week use, running up to 55TB of data per year. Most of our enterprise (Exos), NAS (IronWolf), and Surveillance (SkyHawk) stuff, on the other hand, is rated for 24x7 use, pushing from 180 to 550TB of data per year, depending on the particular model/line. It has a lot to do with not just the hardware of the drive, but also how the firmware is designed to operate.
  8. It won't decrease longevity like a SSD will but random reads get slower when there is more space filled for it to check. You should be defragging spinning disks periodically. That will move related blocks closer.
  9. failboat said:
    It won't decrease longevity like a SSD will but random reads get slower when there is more space filled for it to check. You should be defragging spinning disks periodically. That will move related blocks closer.


    Okay I believe I understand a little bit better now.

    So getting kind've off the original topic somewhat but just to cement the concept...

    When I defrag a disk, you're saying I'm moving related blocks closer. As in (correct me if I'm wrong), I'm moving say...memory blocks of a program that may have been scattered through regular use of the drive, and condensing them so that when the drive goes to read said program, it doesn't have to jump all over the place to find the required data.

    Also, when I'm defragging, am is it simply condensing those memory blocks or is it also physically moving those condensed blocks closer to the center of the drive, so that the data can be accessed faster? (Or does this also depend on how the drive is constructed, or am I wrong all together?)
  10. Best answer
    testtube5 said:
    failboat said:
    It won't decrease longevity like a SSD will but random reads get slower when there is more space filled for it to check. You should be defragging spinning disks periodically. That will move related blocks closer.


    Okay I believe I understand a little bit better now.

    So getting kind've off the original topic somewhat but just to cement the concept...

    When I defrag a disk, you're saying I'm moving related blocks closer. As in (correct me if I'm wrong), I'm moving say...memory blocks of a program that may have been scattered through regular use of the drive, and condensing them so that when the drive goes to read said program, it doesn't have to jump all over the place to find the required data.

    Also, when I'm defragging, am is it simply condensing those memory blocks or is it also physically moving those condensed blocks closer to the center of the drive, so that the data can be accessed faster? (Or does this also depend on how the drive is constructed, or am I wrong all together?)


    It moves everything to the outside of the disk and sorts related data closer. If you had something like -,-,x,y,-,-,x,y it would makeit x,x,y,y,-,-,-,- this will reduce your random reads which are slower and make random reads faster. it's not a compression or anything that reduces blocks. this could help your drive size on top of defrag. it will increase cpu usage slightly not much. defragging manually only applies to windows because other filesystems, e.g. ex4, do it by default.
  11. failboat said:
    testtube5 said:
    failboat said:
    It won't decrease longevity like a SSD will but random reads get slower when there is more space filled for it to check. You should be defragging spinning disks periodically. That will move related blocks closer.


    Okay I believe I understand a little bit better now.

    So getting kind've off the original topic somewhat but just to cement the concept...

    When I defrag a disk, you're saying I'm moving related blocks closer. As in (correct me if I'm wrong), I'm moving say...memory blocks of a program that may have been scattered through regular use of the drive, and condensing them so that when the drive goes to read said program, it doesn't have to jump all over the place to find the required data.

    Also, when I'm defragging, am is it simply condensing those memory blocks or is it also physically moving those condensed blocks closer to the center of the drive, so that the data can be accessed faster? (Or does this also depend on how the drive is constructed, or am I wrong all together?)


    It moves everything to the outside of the disk and sorts related data closer. If you had something like -,-,x,y,-,-,x,y it would makeit x,x,y,y,-,-,-,- this will reduce your random reads which are slower and make random reads faster. it's not a compression or anything that reduces blocks. this could help your drive size on top of defrag. it will increase cpu usage slightly not much. defragging manually only applies to windows because other filesystems, e.g. ex4, do it by default.


    Great, thanks for the thorough answer.

    Last question, what increases CPU usage? You mean *while* defragging right? (I do know this, but if you mean something else I wasn't aware)
  12. testtube5 said:
    failboat said:
    testtube5 said:
    failboat said:
    It won't decrease longevity like a SSD will but random reads get slower when there is more space filled for it to check. You should be defragging spinning disks periodically. That will move related blocks closer.


    Okay I believe I understand a little bit better now.

    So getting kind've off the original topic somewhat but just to cement the concept...

    When I defrag a disk, you're saying I'm moving related blocks closer. As in (correct me if I'm wrong), I'm moving say...memory blocks of a program that may have been scattered through regular use of the drive, and condensing them so that when the drive goes to read said program, it doesn't have to jump all over the place to find the required data.

    Also, when I'm defragging, am is it simply condensing those memory blocks or is it also physically moving those condensed blocks closer to the center of the drive, so that the data can be accessed faster? (Or does this also depend on how the drive is constructed, or am I wrong all together?)


    It moves everything to the outside of the disk and sorts related data closer. If you had something like -,-,x,y,-,-,x,y it would makeit x,x,y,y,-,-,-,- this will reduce your random reads which are slower and make random reads faster. it's not a compression or anything that reduces blocks. this could help your drive size on top of defrag. it will increase cpu usage slightly not much. defragging manually only applies to windows because other filesystems, e.g. ex4, do it by default.


    Great, thanks for the thorough answer.

    Last question, what increases CPU usage? You mean *while* defragging right? (I do know this, but if you mean something else I wasn't aware)


    compression does if you turn on full drive compression.

    defragging is very slow. you will want to do that over night.
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