512GB SSD only 500GB?

Discussion in 'iMac' started by jazzer15, Dec 20, 2015.

  1. jazzer15 macrumors 6502

    Joined:
    Oct 8, 2010
    #1
    Why does a 512GB SSD show capacity (not available space) of just under 500GB in Disk Utility? Is there a portion that is hidden or is Apple really using a 500GB drive?
     
  2. rapicell macrumors regular

    Joined:
    Mar 20, 2013
    #2
    That's how drives work, regardless of brand. Hence why everything tends to say "Actual formatted space may differ"
     
  3. jazzer15 thread starter macrumors 6502

    Joined:
    Oct 8, 2010
    #3
    I realize that actual space availability after formatting will be less than the listed capacity of the drive, but is it normal to actually indicate a lower capacity? My 2TB external drives show a capacity of 2TB even though less is actually available. And my 2TB internal drive on my 2009 iMac indicates a capacity of 2TB in disk utility.
     
  4. T'hain Esh Kelch macrumors 601

    T'hain Esh Kelch

    Joined:
    Aug 5, 2001
    Location:
    Denmark
    #4
    Look up the difference between gibibytes and gigabytes.
     
  5. Erdbeertorte macrumors demi-goddess

    Erdbeertorte

    Joined:
    May 20, 2015
    Location:
    Castle Grayskull, Eternia
    #5
    Sorry, I can't explain it really good in english:

    They just use the factor 1000 instead of 1024 nowadays for promoting the size of drives. Normally 1024x1024x1024 Byte = 1GB, now it's 1000x1000x1000 Byte = 1GB.

    https://en.wikipedia.org/wiki/Gigabyte
     
  6. jazzer15, Dec 20, 2015
    Last edited: Dec 20, 2015

    jazzer15 thread starter macrumors 6502

    Joined:
    Oct 8, 2010
  7. jazzer15 thread starter macrumors 6502

    Joined:
    Oct 8, 2010
  8. hiddenmarkov macrumors 6502a

    Joined:
    Mar 12, 2014
    Location:
    Japan
    #9

    Your externals may setup different than a "system" internal driver.

    they may also setup differently based on how vendor work their magic.

    Or the vendor used a more specific rating for size. They may have based on 1024 not 1000 so rating will be the same. there are no standards sadly for electronics marketing. They can do what they want. I used to be into car audio. Quite common to see what we called ILS rated amps advertised. ILS meaning the only way you would get the outputs they listed was If Lightning Strikes (ILS) to get the source voltage to make that happen.

    Disk utility can also not give 100% accurate info. Quite a few times command line disk info commands and disk utility have not seen eye to eye for me. I tend to trust the CLI in these cases.
     
  9. jazzer15 thread starter macrumors 6502

    Joined:
    Oct 8, 2010
    #10
    Thanks everyone. Nota big deal. Just wanted to understand what was going on. The Apple support document April posted explains it well.
     
  10. dogslobber, Dec 20, 2015
    Last edited by a moderator: Dec 21, 2015

    dogslobber macrumors 68020

    dogslobber

    Joined:
    Oct 19, 2014
    Location:
    Apple Campus, Cupertino CA
    #11
    Many years ago drive manufacturers found they could artificially increase their perceived hard disk size by pretending there were 1000 bytes in 1KB, and proceeded to call it 1KiB. Well that daftness was extended to MiB and TiB but is just a con and is a fake marketing ploy. Apple was equally daft a few OS X releases back when they decided to use the GiB marketing ploy when reporting free bytes in Finder.

    It's all marketing BS.

    It looks like marketing BS has won now that the default is taken to mean 1000^2. Quite sad really as 1000^2 isn't a power of 2 that the computer knows how to handle.

    It looks like marketing BS has won now that the default is taken to mean 1000^2. Quite sad really as 1000^2 isn't a power of 2 that the computer knows how to handle.
     
  11. santaliqueur macrumors 6502a

    Joined:
    Aug 7, 2007
    #12
    It's also complete garbage they are allowed to say "actual formatted capacity may be less". Formatted or not, the way you are defining it MAKES IT less. Nothing to do with formatting.

    This ridiculous tactic is actually built into OS X now, been this way for a few versions. My new iMac came with a "500GB" SSD, which is actually just 500,277,790,720 bytes. 500 billion bytes is not 500GB, but OS X now displays it as 500GB everywhere you look. Sad.
     
  12. Samuelsan2001 macrumors 603

    Joined:
    Oct 24, 2013
    #13
    Not sad at all just providing the information you need in the simplest way possible anything else is just technical jargon for the likes of the geeks on this forum, most people couldn't care less and half of them probably couldn't even tell you how much space their computer has and what they have stored on it.
     
  13. maflynn Moderator

    maflynn

    Staff Member

    Joined:
    May 3, 2009
    Location:
    Boston
    #14
    It is very confusing and I think apple made it more so when they changed how they count megabytes/gigabytes, i.e., changing from base 2 to base 10
     
  14. santaliqueur macrumors 6502a

    Joined:
    Aug 7, 2007
    #15
    It is sad that I have a 466GB SSD in this machine, but because it has 500 billion bytes, OS X tells me it's 500GB. It's not.
     
  15. Hellhammer Moderator

    Hellhammer

    Staff Member

    Joined:
    Dec 10, 2008
    Location:
    Finland
    #16
    For what it's worth, the SI prefixes (kilo, mega, giga...) predate any computer. A kilo is 1,000, not 1,024. The problem is that back in the days someone decided that 1,024 is "close enough", so calling it a kilo would be fine. Computers should never have adopted SI prefixes because of their binary foundation, and we have kibi, mebi and gibi prefixes for those.
     
  16. Erdbeertorte macrumors demi-goddess

    Erdbeertorte

    Joined:
    May 20, 2015
    Location:
    Castle Grayskull, Eternia
    #17
    I also think it's wrong. But i seems something has changed since we learned that 500 GB should be 536,870,912,000 Bytes. Words like Gibibyte did not officially exist before the end of the 1990s. I first read about those words last year and never heard it before.

    500,000,000,000 Byte / 1024 / 1024 / 1024 = 465,66 seems at least reasonable an that new case.

    But why does iOS display 113GB for an 128GB iPhone when

    128,000,000,000 Byte / 1024 / 1024 / 1024 = 119,21 ?

    And 1GB of RAM is still 1024MB nowadays...

    Seems everything a little confusing if there are different rules for HDDs/SSDs, phone storages, system/graphics RAM and maybe some other stuff...

    I think I'm getting old... :(:oops:
     
  17. Samuelsan2001 macrumors 603

    Joined:
    Oct 24, 2013
    #18
    What is sad is that you can't just accept that the numbers mean nothing and that it is an arbitrary unit used to describe how much space your computer has for information, the numbers mean nothing they could have called it 500 memory units for all it matters.

    As long as the files that go onto it scale with the discrepancy (and they do everyone uses the same units no matter what they really mean) it matters not one whit.

    All your maths is just an excercise in futility and pointless anal nitpicking.
     
  18. maflynn Moderator

    maflynn

    Staff Member

    Joined:
    May 3, 2009
    Location:
    Boston
    #19
    That war was waged and lost when OS X was updated to use base 10 to report space. You may not like it, but its the world we live in.

    btw, I never even look at what the stated drive capacity is vs, what I see. Only that I'm able to have sufficient storage for my data.
     
  19. santaliqueur macrumors 6502a

    Joined:
    Aug 7, 2007
    #20
    Then surely my "128GB" iPhone will display 128GB just to satisfy people like you? Right? NOPE! Shows 114GB capacity. Apple doesn't even share "the same units" between their two major operating systems.

    Would you buy a gallon of milk and get 7 quarts for the same price, because they had a different way of measuring volume?

    What about if you bought a house? This house is 2000 sqft, but we used different equipment to measure the rooms, and it's actually 1700 sqft. But we'll call it 2000, and you still pay the same price.

    What's sad is that this never used to be an issue, and with so much lobbying and money spent, people like you just accept it and say "just ignore it, you're being anal".
     
  20. santaliqueur macrumors 6502a

    Joined:
    Aug 7, 2007
    #21
    Then why is it still calculated in base 2 for iOS? Apple can't even keep the units straight on their own operating systems.
     
  21. Hellhammer Moderator

    Hellhammer

    Staff Member

    Joined:
    Dec 10, 2008
    Location:
    Finland
    #22
    iOS reports the capacity available to the user. The operating system (iOS) and pre-installed apps take several gigabytes and cannot be deleted, unlike in OS X. In addition, there's space reserved for over-provisioning etc.

    The units are the same in both iOS and OS X.
     
  22. Samuelsan2001 macrumors 603

    Joined:
    Oct 24, 2013
    #23
    As hellhammer says in iOs you are shown the available space not the full space of the drive as you get in OSX, what is sad is that you can't accept when you are being silly and talking nonsense.
     
  23. maflynn Moderator

    maflynn

    Staff Member

    Joined:
    May 3, 2009
    Location:
    Boston
    #24
    You seem rather worked up over this issue. As noted, its working as OS X works, so there's no diconnect between the two operating systems.
     
  24. santaliqueur macrumors 6502a

    Joined:
    Aug 7, 2007
    #25
    iOS takes up 18GB of space? Or what you're saying is not correct?

    My "128GB" iPhone says it has 114GB capacity. 128 billion bytes is 119GB. iOS and its associated apps take up the remaining 5GB difference. The units are not the same in iOS and OS X.
     

Share This Page