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Amount of RAM does not add up

Discussion in 'OcUK Full Systems & Bundles' started by Tim Hutchinson, Jun 12, 2018.

  1. Tim Hutchinson


    Joined: Mar 30, 2018

    Posts: 5

    Hi All,
    I have an Asus B350Prime mobo, with two 4GB sticks of DDR4 ram, but I am getting very mixed reports on the total ram.
    • BIOS says 4GB in slot A2, 4GB in slot B2. Total memory = 4GB
    • Windows (W10 pro) reports 8GB total, but only 3.94 usable
    • memtest only finds 4GB
    Any body come across this before, or could offer any advice?
  2. skyripper

    Wise Guy

    Joined: Jul 19, 2011

    Posts: 1,678

    Using 32-bit version of windows?
    Using onboard Video rather than a gfx card?
  3. MagicBoy


    Joined: Oct 18, 2002

    Posts: 15,335

    Location: South Manchester

    Sounds like you have 32-bit Windows installed...
  4. Tim Hutchinson


    Joined: Mar 30, 2018

    Posts: 5

    Windows reports 64bit os and 64bit cpu (system properties screen). Could this be wrong?
    If I boot to usb and run memtest it does not produce any errors but only finds 4gb ram. Surely booting to usb like this would eliminate a fault with the os?
  5. Armageus


    Joined: May 19, 2012

    Posts: 8,815

    Location: Spalding, Lincolnshire

    Depends if the usb memtest is also 32bit?
  6. Threepwood


    Joined: Sep 29, 2011

    Posts: 4,088

    Location: Monkey Island

    Update BIOS, run MEMTEST.
  7. ~>Dg<~


    Joined: Jun 1, 2006

    Posts: 30,190

    Location: Notts

    also make sure you have the ram in the correct slots.some asus boards can be dicks for this.
  8. Gimpymoo


    Joined: May 31, 2005

    Posts: 14,420

    Location: Nottingham

    Have you tried resetting BIOS to defaults?
  9. Quartz


    Joined: Apr 1, 2014

    Posts: 5,988

    Location: Aberdeen

    This is correct per page 1-12 of the manual. Are the DIMMs an exact match?
  10. Phemo


    Joined: May 6, 2004

    Posts: 5,137

    Location: Portsmouth

    Could also be worth reseating the CPU if all else fails. I've seen this sort of thing happen in the past, though usually with socket 1366 based i7s where the 3rd memory channel wasn't working correctly.

    Edit: Ignore that actually, I missed that it was an AM4 board so since it isn't an LGA socket, the chance of that making any difference is minimal.