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  1. #1
    Creator MrLubo's Avatar
    Join Date: Jan:2006
    Location: ON
    Posts: 84

    512MB RAM DDR PC2100 . 1GB DDR PC3200 . , ? - ?
    iPad | iPod | iPhone |iSiktir bee

  2. #2
    The Black Beret  's Avatar
    Join Date: Oct:2006
    Location:
    Posts: 8,417
    Quote Originally Posted by MrLubo View Post
    512MB RAM DDR PC2100 . 1GB DDR PC3200 . , ? - ?
    , - . , . - , , swap- .

    . . - .
    Molṑn Labe

    , .

  3. #3
    Registered User
    Join Date: Sep:2007
    Location: Bulgaria
    Posts: 20
    ! . . . , , . ? 256MB PC2700 DDR SDRAM. verest . , ? , .

  4. #4
    HAL 9000 oldschool's Avatar
    Join Date: Sep:2007
    Location:
    Posts: 47
    DDR , .. PC3200 (400mhz) PC2700 (333mhz), - , .. 333mhz.

    ( '') high low density. low density , high density 10%.

    high density . .

    ECC non-ECC , , buffered unbuffered . .

    , .

    high / low density :

    Keep in mind this explanation is for non-ECC modules, while the one I give below based on Wkipedia is for ECC modules - the bits per rank are different, i.e. 64 for non-ECC and 72 for ECC!

    ======================================== ========
    "Standard' RAM chips are organized a DEPTH x 8 Bits. E.g. 32x8, 64x8,
    etc. That means 8 of the chips make up a 64 bit wide rank (memory bus
    is 64 bits wide). "Double Sided" is an old term to describe a stick
    with 16 chips, 8 on each side. And with DEPTH x 8 chips that makes for
    2 ranks (or, again in an older style terminology: 2 'banks').

    'High Density' chips are DEPTH x 4 bits so it takes 16 to make a 64
    bit wide memory rank. And this is why "double sided" is no longer the
    favored description because when x8 chips are used "Double sided"
    means "double rank" but with x4 chips it takes both sides and 16 chips
    to make the ONE, single, rank.

    Now to the problem. A memory 'slot' is usually designed for 'standard'
    x8 chips and memory sticks containing 2 ranks. That is how the
    'capacity' will be described. I.E. the K7S5A says it can handle up to
    "1 gig" with two DDR slots, and that means 512Meg per slot, which
    means 256 Meg PER RANK. (2 ranks per slot, 2 slots, etc)

    But a 'high density' memory stick crams the 512 Meg into ONE RANK by
    using 16 deeper (twice as deep) x4 bit width chips. And this is how
    they arrive at the confusing term 'high density'. The chips themselves
    are no higher in density than the x8 chips but since they are
    organized as x4 they can cram more 'bytes' into a single rank because
    16 chips make up a rank rather than 8, not that it helps make the
    stick itself any 'higher' in 'density' because you can still only get
    16 chips mounted on the thing.

    So, a 512 Meg 'high density' stick puts 512 Meg in ONE RANK and a
    'standard' density 512 Meg stick is two 256 Meg Ranks. Same size, same
    'density'. It's the RANK organization that's different.

    Since the memory slot on a K7S5A is two 256 Meg Ranks, a standard
    density 512 Meg stick will work but a 'high density' 512 Meg stick
    will not.

    However, a 'high density' 256 Meg stick probably will since it crams
    the 256 Meg into ONE RANK and the K7S5A can handle 256 Meg ranks.

    For example, I'm running SDRAM on my K7S5A and, as it turns out, one
    is 'standard' x8 density and the other is 'high density x4. But
    they're both 256 Meg sticks and they both work. Damn irritating,
    however, as they were both bought at the same time inside the same
    package label, and same part number, with 16 chips on each so they
    look identical (Kingston) but they are NOT the same thing. Doesn't
    matter to my K7S5A but it means I can not use the 'high density' one
    in my other motherboards because they support 128 Meg ranks (256 Meg
    per slot but NOT in 'high density').

    So, in a nutshell, if you're looking for 512 Meg sticks, make sure the
    spec says they use x8 chips. But, if you're not trying to get 1 gig
    then two 256 meg 'high density' sticks will be cheaper."

    ======================================== ========
    Also check the example table near the bottom of this page: http://en.wikipedia.org/wiki/DDR_SDRAM

    Example: Variations of 1 GiB PC2100 Registered DDR SDRAM module

    Some explanations on the table:

    They use 1GB module of ECC memory as example. The number of chips in ECC is multiple of 9, e.g. 36 or 18 chips in the whole module. For non-ECC the multiple is 8, e.g.. 16 chips.

    The first three columns give the number of chips in module X the individual chip size, e.g. 36 x 256Mibit (divide 256 to 8 to get MiB, i.e. 256/8 = 32 MiB) = 1GiB (i.e. 36 chips x 32 MiB)

    Now the last two colums. Keep in mind that DDR memory bus width per channel is 64 bits (72 for ECC memory).
    Take the first row for example: 64M is a number of storage units (64 million), x4 (pronounced by 4) number of bits per chip. 4 bits per chip X 36 chips in module = 144 bits (distributed in 2 rows/ranks it makes exactly 72 bits per rank for ECC memory).

    Don't let the numbers 64M and 128M confuse you. They are only the number of storage units in millions and are not used in the calculations.

    Now you need to know what memory density does you motherboard support in order to make the right decision about buying memory..

  5. #5
    Creator MrLubo's Avatar
    Join Date: Jan:2006
    Location: ON
    Posts: 84
    oldschool

    , - , - , . : - 512- 1 ? , - - ( - ). ( ) - -. ?
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  6. #6
    a.k.a. Kal KaloyanP's Avatar
    Join Date: Dec:2005
    Location: UK
    Posts: 3,750
    , Everest.
    D80; 50/1.8D; Tamron 70-300; 18-55 VR;

  7. #7
    Creator MrLubo's Avatar
    Join Date: Jan:2006
    Location: ON
    Posts: 84
    - 1,5 , - . .
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