Memories bit bandwidth, memories banks, bank group, bus lane, address lane and ram pre-fech

Discussion in 'Tech Discussion' started by xiazixin, Nov 21, 2019.

Tags:
  1. xiazixin

    xiazixin Well-Known Member

    Joined:
    Dec 7, 2017
    Messages:
    1,386
    Likes Received:
    657
    Reading List:
    Link
    Caution, I write this for general public to understand the concepts of Drams, this articles is by no way accurate for research or academic purpose. please consult professionals for more accurate and detailed post. And if you are professional, please Point out the mistake for this. By no way I took any formal class/lessons on this.

    Honesty I know this for quite some time, and since @Jeebus mistaken memories bits in one of the post, so I try to explain. when I was writing this post, I did search up for English articles on it, Seriously all of them are University research papers or some research institute. And with my weak English, other than a few terms I have no Idea what the paper is writing. As some one who do technical translations, I don't really do translations so deep, and I don't have a Professor to edits and proofreads for me.
    (I should really backup this and write it on my site instead, In case novel updates fail to auto save for me or runsing delete this post just as the other one.)
    What is memories data bus bandwidth for a Ram stick?
    So what do I mean PC use 8bit memories.
    One thing, our PC use stranded 8bits memories address, as the picture below says it on data bus.
    below is a 8bit load out. seems to be ddr3 (caution). basically a 8bits memory addresses and don't have bank groups.
    upload_2019-11-21_15-44-49.png
    so on top is a 64bit memories bus also know as 8 bytes
    upload_2019-11-21_17-36-13.png
    So basically each chips is 8 bits.
    for memories I think each is 16 bits.
    for 1 channel, can carry 64bits
    and 128bits for dual channel.

    Edit's it kinda gets confusing. as there is pre-fetch.



    From what I known, Some older servers run on 4 bits memories , general everyday PC runs on 8 bits memories and graphic cards runs on 16 bits memories (only some or IDK all?).


    And strangely almost all AMD CPU before ryzen works with 4bits ram and 16bits ram, so there is the terms AMD Only rams in Ebay and other online shops for a cheap price.(they are recycle ram die removed from unwanted servers, server grade ram die have a long life so Chinese manufacture reuse them for as AMD only ram to not be wasteful) There are many people ask what is AMD only ram and those helpful fools only tell them that all rams work in both Intel and AMD cpu the same. which is a disastrous mistakes as Intel Cpu cant lit up from this. https://www.google.com/search?q=Amd+only+ram.

    [​IMG]
    Note: Intel can only run 8bit ram, AMD before ryzen can run 4bit, 8bit. 16bits ram. AMD YES!!!
    Today, AM4 mother boards with DDr3 ram slots "upgrade" still can run 4bits and 16bits ram with an older pre ryzen CPU. (which I have mention AMD only ram in 100 usd pc builds) Only monster in tuaba do that now.
    Memories bandwidth
    memories bandwidth = memories clock*memories bus. memories bus = bus lane*memories bit width.
    let say I have my dual channel clock at 3800mhz,
    my memories bandwidth would be 3800M*128bit = 486400Mbps
    which is 468.4Gbps
    also known as 60.8GiB/s

    Memories addressing
    upload_2019-11-21_18-22-43.png
    this is the addressing for micron E-die, which is one of my homework for overclocking C9bjz.
    if you want to learn more about it, you can download the documentation from here.
    The graph for bus width here.
     

    Attached Files:

    Last edited: Nov 21, 2019
    Deleted member 155674 likes this.
  2. LNreader

    LNreader Courting Death

    Joined:
    Aug 16, 2016
    Messages:
    562
    Likes Received:
    1,227
    Reading List:
    Link
    Just download more RAM
     
    thepope and xiazixin like this.