Puzzled with enabling Dual Channel memory on my HP laptop...

Discussion in 'Memory' started by odessouky, Feb 13, 2018.

  1. odessouky

    odessouky n00bie

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    Aloha everyone...

    I'm an old timer, my previous username was oymd, but for some reason I am not able to login with my old username...

    My last post seems to be in 2008!!

    Anyways...I have been using MACs exclusively since 2008, but I have been recently given a Windows Laptop to use for some work related matters...

    Its a HP EliteBook 745 G3; and has the AMD PRO A12-8800B; AMD Carrizo FCH 11

    It came stock with a single Samsung 8GB DDR3 12800 1600MHz memory stick

    First thing I did is get an identical Samasung 8GB stick to run in DUAL CHANNEL mode..

    For some reason the laptop still runs in SINGLE CHANNEL MODE?

    BIOS and CPU-Z show the full 16GB memory properly recognized, but its running in SINGLE CHANNEL? GPU-Z shows AMD Radeon R7 Graphics chip with Bus Width 64bit, when it should be 128bit if Dual Channel is recognized?

    Tried everything to find a setting to enable dual mode, but as far as I can remember from my PC days, DUAL CHANNEL should just get activated automatically?

    I've posted some pics of CPU-Z and GPU-Z

    Can some one help please?

    Thanks
     

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  2. pendragon1

    pendragon1 [H]ardForum Junkie

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    i dont think it works that way with the gpu but you are right that its only running in single channel mode. the hp site does say it support dual but no info if you have to enable it in bios or anything. of btw, there is a new bios from jan '18. those stick of ram are very close but not quite matched, just models are a bit different. not sure if that would cause an issue. do you have another matched pair of any size that you could test in it to rule that out? dig through the bios and look for anything ram relate, ganged or unganged that kinda stuff. maype post some pics of the bios cause i cant seem to find any...
     
  3. odessouky

    odessouky n00bie

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    Hi
    Thanks for your reply
    I went through every single page of the BIOS, EFI, etc
    There is no where a setting for enabling DUAL CHANNEL memory.
    I thought it should be automatic.
    Yeah, the ram sticks are not a matched pair, but are fairly similar with similar CAS timings and part numbers.

    I did the same exact thing for my colleagues HP Laptop, but that one was a 840 G3 model with an i56200, but actually installed a Crucial 8GB ram stick to match the existing Samsung 8GB stick that was stock in his laptop, and BOOM, instantly on power up CPU-Z confirmed DUAL Channel memory operation.

    Did not need to fiddle with his BIOS at all?
     
  4. odessouky

    odessouky n00bie

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    Just to clarify, On the HP 840 G3 which runs an INTEL i5 6200U, with DDR4, I installed UNMATCHED Samsung & Crucial DDR4 8GB modules, and they ran in DUAL CHANNEL mode with no problem what so ever...
     
  5. pendragon1

    pendragon1 [H]ardForum Junkie

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    your unit is supposed to do it and it should be auto. if you dont have a matched set to try the only other thing i can suggest is contacting HP to see what they say.
     
  6. odessouky

    odessouky n00bie

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    So, today after work I decided to try something silly..

    I switched the 2 ram modules...The one that came stock with the laptop went in to DIMM slot 2, and the new one I sourced from ebay went in to DIMM slot 1...and voila...it worked...

    CPU-Z now notes dual channel memory..

    Geekbench compute score went from 16000 up to 23500...

    GPU still reported in GPU-Z as 64 bit though...

    When I did the same with the i5 6200U with Intel HD 520 GPU, once i went dual channel memory, the bus width went from 64 bit to 128bit..

    It seems the AMD R7 GPU behaves differently to the integrated Intel graphics..
     
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  7. pendragon1

    pendragon1 [H]ardForum Junkie

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    glad you got i going. didnt suggest that, just assumed you had already...
     
  8. odessouky

    odessouky n00bie

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    Thanks for your help though...

    any logical or scientific reason as to why it would work when I switched them around??
     
  9. pendragon1

    pendragon1 [H]ardForum Junkie

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    bios prob noticed the difference and did a full test/settings change. did it take any longer to boot the first time after you switched them?
     
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  10. odessouky

    odessouky n00bie

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    yeah...you know what...after today's swap, I noticed a little lag on startup...screen went blue...and got that circling dot thing...and it took about an extra 3-4 seconds before desktop loaded..

    But over the past few days, I did all sorts of quick and extended memory testing in BIOS, and it never picked up the Dual Channel thing....

    But yeah, u're right...today startup definitely lagged for a few seconds before the new setup recognized dual channel...
     
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  11. pendragon1

    pendragon1 [H]ardForum Junkie

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    glad to help and that you got it goin :)
     
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  12. odessouky

    odessouky n00bie

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    overall it doesn't really matter much...it's a crap laptop anyways...only for work...but I enjoyed the challenge to get it to work!!!
     
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