why only 1.98GB?

Discussion in 'Windows, Linux & Others on the Mac' started by daneoni, Oct 31, 2006.

  1. daneoni macrumors G4

    daneoni

    Joined:
    Mar 24, 2006
    #1
    Why only 1.98GB recognised instead of 2GB in XP?
     
  2. majorp macrumors 6502

    Joined:
    Nov 28, 2005
    Location:
    UK !!!
    #2
    what computer is it?
     
  3. daneoni thread starter macrumors G4

    daneoni

    Joined:
    Mar 24, 2006
    #3
    15" MBP
     
  4. majorp macrumors 6502

    Joined:
    Nov 28, 2005
    Location:
    UK !!!
    #4
    hmm, good question. I don't know but i wouldn't worry about it.

    anybody else?
     
  5. sulhaq macrumors regular

    sulhaq

    Joined:
    Jul 29, 2006
    #5
    Significant Figure conversion error and Rounding off error. 1 Kilo does not mean 1000 in the computer world it means 1024. If you look in system information 2.33ghz translates to 2327 Mhz. Similarly due to this error the total RAM is 1.98gb which windows shows correctly. OSX just rounds it off to 2gb and doesn't care about conversion errors.
     
  6. daneoni thread starter macrumors G4

    daneoni

    Joined:
    Mar 24, 2006
    #6
    It also seems the merom chip can support 977MHz of FSB. So 677 must be very limiting but its better than 167Mhz...ugh!
     
  7. daneoni thread starter macrumors G4

    daneoni

    Joined:
    Mar 24, 2006
    #7
    I see
     
  8. PlaceofDis macrumors Core

    Joined:
    Jan 6, 2004
    #8
    um, no? 1024 + 1024 = 2048 technically then, not 1.98 no?
     
  9. gekko513 macrumors 603

    gekko513

    Joined:
    Oct 16, 2003
    #9
    We're talking about RAM here, right? A quick google search tells me that this is common in Windows XP and isn't related to the MacBook (Pro) in particular. I haven't found why, yet.
     
  10. majorp macrumors 6502

    Joined:
    Nov 28, 2005
    Location:
    UK !!!
  11. drval macrumors member

    Joined:
    Oct 19, 2006
    #11
    This is really out of the dusty halls of long forgotten trivia but, yes, it's 2048. There is always a 64K core kernel so take that off and now your're at:

    2048
    - 64
    ____
    1984

    So with decimal rounding/truncation, you get 1.98(4) GB.

    So, yes, Windows is "more" precise in this regard but it may well be that Mac has a differet kernel allocation algorithm -- so that 2(.000) GB might actually be right!
     
  12. PlaceofDis macrumors Core

    Joined:
    Jan 6, 2004
    #12
    thank you for that. honestly. its always nice to know the specifics of these things than to leave them up in the air. :D
     
  13. MRU macrumors demi-god

    MRU

    Joined:
    Aug 23, 2005
    Location:
    Ireland
    #13
    Also even if you have more than 2gb - windows xp 32bit will still report 1.98
     
  14. drval macrumors member

    Joined:
    Oct 19, 2006
    #14
    I believe that has to do with how 32-bit Windows handles "blocks" of RAM. The largest addressable block is "2GB" so, having more doesn't give you an overall "larger" block as far as that goes; but it does give you almost a second such block.

    In otherwords, accessing any address space over 2 GB will be handled more like a memory swap than anything else.

    This means that all that the 32-bit Windows kernel "sees" are blocks up to 2 GB.
     

Share This Page