1. This forum section is a read-only archive which contains old newsgroup posts. If you wish to post a query, please do so in one of our main forum sections (here). This way you will get a faster, better response from the members on Motherboard Point.

Made a mess of purchasing new memory - please help!

Discussion in 'PC Hardware' started by Dot Net Developer, Nov 2, 2006.

  1. Hi,

    Got 1gb memory PC, needed more memory for scanning large pics, so
    bought 512mb module.

    Fits very snuggly although strangely the plastic "ejector tabs" either
    side of the DIMM bank won't snap back in to place to secure the new
    memory module. (However I cannot push module in any further - it
    appears to fit well enough.)

    Booting up shows no extra memory though.

    Running utility prog "Sandra" tells me for the "system memory
    controller" section that I only have 2 memory slots, but the
    motherboard has 3 DDR DIMM sites.

    However, the motherboard manual says this (and this is where I think
    I've messed up) "DIMM2 & DIMM3 are sharing"

    Basically, I was hoping for 3 DIMM slots each having 512mb memory
    modules giving me 1.5gb of memory. But I'm still left with just 1gb,
    even though all 3 slots are filled.

    What should I do?

    Thanks, regards, dnw.
     
    Dot Net Developer, Nov 2, 2006
    #1
    1. Advertising

  2. PS ~ I'm not sure if it's my imagination, but my PC seems noticeably
    faster now, especially when handing large pic files, which is why I
    bought the extra memory.

    Strange. Or is it?
     
    Dot Net Developer, Nov 2, 2006
    #2
    1. Advertising

  3. Dot Net Developer

    Arno Wagner Guest

    Previously Dot Net Developer <> wrote:
    > PS ~ I'm not sure if it's my imagination, but my PC seems noticeably
    > faster now, especially when handing large pic files, which is why I
    > bought the extra memory.


    > Strange. Or is it?


    If the ''levers'' ind the side do not snap in, tnen the memory is
    wrong. Or insterted wrong. Period. If you are lucky, then you have
    not actually killed the memory chips. But you might have. I did this
    once by inserting a mamory chip 180 degrees turned. Fortunately
    I smelled the error immediately on turning the PC on, and only
    one of 5 power tabs had burned off. It was still usable.

    Morale: Don't turn a PC on when you are not totally sure the
    memory is inserted correctly.

    Arno
     
    Arno Wagner, Nov 2, 2006
    #3
  4. I got the "levers" issue fixed - I pulled out the memory module and
    refitted it, this time correctly.

    I have tested the new module and it works fine.

    However, I am unable to have all three 512mb modules working together.
    I can have any 2 working, but not all 3.

    The error message I get is a serious blue screen message on bootup -

    Your BIOS is not fully ACPI compliant. Please visit
    www.hardware-update.com to update your BIOS.

    I am going to check this out now...

    Regards, dnw.
     
    Dot Net Developer, Nov 2, 2006
    #4
  5. Successfully upgraded bios.

    However, when I add the extra memory, I still get ACPI compliant error
    message.

    Wondering whether my mobo can handle ACPI - trouble is, can't see any
    way of disabling it in the bios options on bootup. I can have either
    state S1 or S3, but nothing else.

    I have abit BD7II mobo. I have turned off all power management
    features in XP.

    Do I need a new mobo to be able to have 3 lots of 512mb? (Manual says
    I can have max of 2gb, so I'm not hitting a limit in this regard)

    Thanks, regards, dnw.
     
    Dot Net Developer, Nov 3, 2006
    #5
  6. "Dot Net Developer" wrote

    > Do I need a new mobo to be able to have 3 lots of 512mb? (Manual says
    > I can have max of 2gb, so I'm not hitting a limit in this regard)


    Found this at

    http://www.futurehardware.in/188994.htm
    "ABIT BD7II-RAID, max memory 2GB (in theory?)..."

    The 845E Northbridge drives a maximum of four banks of
    memory. A three slot motherboard has room for six banks of
    memory, meaning, at any one time, only four of the six
    banks have control signals available to drive them.

    DIMM slot 0 is "normal" and can accept a double sided DIMM.

    DIMM slots 1 and 2 are "crosswired", allowing one double
    sided DIMM in DIMM slot 1 or two single sided DIMMs to be
    used in slot 1 and slot 2.

    845E Northbridge datasheet - PDF page 113
    ftp://download.intel.com/design/chip...s/29074201.pdf

    "Maximum of two DIMMs, single-sided and/or double-sided"

    SCS0# -------- DIMM 0 side A

    SCS1# -------- DIMM 0 side B

    +----- SCS2# -------- DIMM 1 side A
    |
    | +-- SCS3# -------- DIMM 1 side B
    | |
    | +----------------- DIMM 2 side A
    |
    +-------------------- DIMM 2 side B

    When you plug a single sided DIMM into the DIMM 1 slot, it uses
    SCS2# chip select signal. A single sided DIMM in DIMM 2 slot uses
    SCS3# chip select signal. If a chip select signal is used by
    more than one side of a DIMM, chaos results. Plugging three
    double sided DIMMs would cause that chaos.

    Most people will use two double sided DIMMs on 845 based boards,
    leaving the third slot unused, because there are no more chip
    select signals left to address the third slot. And that is
    why the motherboard has a limit of 2GB (2x1GB) stated in the
    user mahual, as a third 1GB DIMM could not be accessed.
     
    MasterBlaster, Nov 3, 2006
    #6
  7. Good stuff. Thanks a lot.

    I realise I cannot have 3 dimms. The manual is very poor and should
    have warned me better. I have a spare 512 module I guess I could sell
    on ebay!!

    Cheers, dnw.
     
    Dot Net Developer, Nov 3, 2006
    #7
  8. Dot Net Developer

    Arno Wagner Guest

    Previously Dot Net Developer <> wrote:
    > I got the "levers" issue fixed - I pulled out the memory module and
    > refitted it, this time correctly.


    Ah, yes. Sometimes that is necessary.

    > I have tested the new module and it works fine.


    > However, I am unable to have all three 512mb modules working together.
    > I can have any 2 working, but not all 3.


    That is a typical limitation in todays systems. Often you can have
    only 2 or 4 modules, but not 3. And they need to be identical pairs.

    > The error message I get is a serious blue screen message on bootup -


    > Your BIOS is not fully ACPI compliant. Please visit
    > www.hardware-update.com to update your BIOS.


    > I am going to check this out now...


    I think that message is bogus.

    Arno
     
    Arno Wagner, Nov 3, 2006
    #8
  9. Dot Net Developer

    Arno Wagner Guest

    Previously MasterBlaster <Nobody'> wrote:

    > "Dot Net Developer" wrote


    >> Do I need a new mobo to be able to have 3 lots of 512mb? (Manual says
    >> I can have max of 2gb, so I'm not hitting a limit in this regard)


    > Found this at


    > http://www.futurehardware.in/188994.htm
    > "ABIT BD7II-RAID, max memory 2GB (in theory?)..."


    > The 845E Northbridge drives a maximum of four banks of
    > memory. A three slot motherboard has room for six banks of
    > memory, meaning, at any one time, only four of the six
    > banks have control signals available to drive them.


    > DIMM slot 0 is "normal" and can accept a double sided DIMM.


    > DIMM slots 1 and 2 are "crosswired", allowing one double
    > sided DIMM in DIMM slot 1 or two single sided DIMMs to be
    > used in slot 1 and slot 2.


    Urgh. This is really unlucky. Many miodern boards only
    accept single-sided modules. Then you need to have pairs.
    This special solution is unecessarily confusing and the
    designers should be sacked for incompetence.

    Arno



    > 845E Northbridge datasheet - PDF page 113
    > ftp://download.intel.com/design/chip...s/29074201.pdf


    > "Maximum of two DIMMs, single-sided and/or double-sided"


    > SCS0# -------- DIMM 0 side A


    > SCS1# -------- DIMM 0 side B


    > +----- SCS2# -------- DIMM 1 side A
    > |
    > | +-- SCS3# -------- DIMM 1 side B
    > | |
    > | +----------------- DIMM 2 side A
    > |
    > +-------------------- DIMM 2 side B


    > When you plug a single sided DIMM into the DIMM 1 slot, it uses
    > SCS2# chip select signal. A single sided DIMM in DIMM 2 slot uses
    > SCS3# chip select signal. If a chip select signal is used by
    > more than one side of a DIMM, chaos results. Plugging three
    > double sided DIMMs would cause that chaos.


    > Most people will use two double sided DIMMs on 845 based boards,
    > leaving the third slot unused, because there are no more chip
    > select signals left to address the third slot. And that is
    > why the motherboard has a limit of 2GB (2x1GB) stated in the
    > user mahual, as a third 1GB DIMM could not be accessed.
     
    Arno Wagner, Nov 3, 2006
    #9
  10. Dot Net Developer

    Arno Wagner Guest

    Previously Dot Net Developer <> wrote:
    > Good stuff. Thanks a lot.


    > I realise I cannot have 3 dimms. The manual is very poor and should
    > have warned me better.


    Agreed. This is unexpected behaviour. Not your fault.

    > I have a spare 512 module I guess I could sell on ebay!!


    Best option, I think.

    Arno
     
    Arno Wagner, Nov 3, 2006
    #10
  11. > > Your BIOS is not fully ACPI compliant. Please visit
    > > www.hardware-update.com to update your BIOS.


    > I think that message is bogus.


    Yep - Abit chaos! :eek:)
     
    Dot Net Developer, Nov 3, 2006
    #11
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. Wilson
    Replies:
    10
    Views:
    451
    Wilson
    Dec 10, 2005
  2. Rocket
    Replies:
    0
    Views:
    389
    Rocket
    Aug 8, 2003
  3. pjp
    Replies:
    4
    Views:
    218
  4. johns

    new nVidia drivers are a mess

    johns, Nov 29, 2006, in forum: Nvidia
    Replies:
    0
    Views:
    211
    johns
    Nov 29, 2006
  5. N Williamson
    Replies:
    2
    Views:
    223
    N Williamson
    Mar 18, 2007
Loading...

Share This Page