How to find your real GDDR frequency

Discussion in 'Hardware Components and Aftermarket Upgrades' started by Blacky, Apr 5, 2009.

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  1. Blacky

    Blacky Notebook Prophet

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    Many people ask me how do I know the manufacturers frequencies for the GDDR in video cards. Actually it's not that difficult to find out so I thought of writing a small guide so I that I do not have to explain myself every time and also so that others can figure it out easily.

    I have to give my thanx to GanGstaOne for helping in figuring this out.

    How to figure it out

    Every manufacturer of GDDR memories prints extensive information about the memory on the memory itself, this is usually in the form of a code made up of numbers and letters.


    In the case of Samsung, the code will look something like this
    K4XXXXXXXX-[Suffix]
    The Suffix is usually just 2 characters, other times 4 or even more. But almost always, the last 2 characters of the code are the access time.


    In the case of Hynix, the code is a bit different.
    H5XXXXXXXXX-[XX]X
    The [XX] is the access time code, so its not necessarily the last 2 characters. It is usually the first two characters after the dash.
    On more recent GDDR the access time code is the first two characters of the second line (the line right below the long code on top).

    In the case of Qimonda, its similar to the other two manufacturers but its a bit different for GDDR3 and GDDR5 memories (meanwhile, Qimonda went bankrupt).

    Qimonda - GDDR2/GDDR3
    HYBXXXXXXXXXXXX-[XX]
    Again, the access time code is the number after the dash, the [XX] part in the code above. However, please note that this code may be just one character not two as it is usually for the other manufacturers.

    Qimonda - GDDR5
    IDGXXXXXXXXXX -[XX]
    As above, the access time code is the number after the dash, the [XX] part in the code above.

    I do not know any other method of finding this code besides having physical access to the memory module itself.

    What is the access time/cycle time?

    Simply putting is the fastest time at which the memories are designed to be accessed. This is calculated in ns (nanoseconds). This also means that the access time can be translated into the memory frequency and it is very easy to do this, just divide 1000 by the access time. (Example: 1.6ns means 1000/1.6 = 625 Mhz ). I won't go into details why it is calculated this way.

    So now that you know where do find the access time code on the memory, here is a list of what each code means:

    Code - Access time - Frequency for Samsung GDDR
    25 --- 2.5ns ------ 400Mhz
    22 --- 2.2ns ------ 450Mhz
    20 --- 2.0ns ------ 500Mhz
    19 --- 1.875ns ---- 530Mhz
    18 --- 1.8ns ------ 550Mhz
    16 --- 1.6ns ------ 625Mhz
    15 --- 1.5ns ------ 650Mhz
    14 --- 1.4ns ------ 700Mhz
    12 --- 1.25ns ----- 800Mhz
    11 --- 1.1ns ------ 900Mhz
    1A --- 1.0ns ------ 1000Mhz
    09 --- 0.9ns ------ 1100Mhz
    08 --- 0.8ns ------ 1200Mhz
    7A --- 0.77ns ----- 1300Mhz
    07 --- 0.71ns ----- 1400Mhz
    6A --- 0.66ns ----- 1500Mhz
    06 --- 0.62ns ----- 1600Mhz
    5C --- 0.56ns ----- 1800Mhz
    05 --- 0.5ns ------ 2000Mhz
    04 --- 0.40ns ----- 2500Mhz
    03 --- 0.33ns ----- 3000Mhz
    28 --- 0.28ns ----- 3500Mhz




    Code - Access time - Frequency for Hynix GDDR
    60 --- 6.0ns ------ 166Mhz
    55 --- 5.5ns ------ 183Mhz
    50 --- 5.0ns ------ 200Mhz
    43 --- 4.3ns ------ 233Mhz
    40 --- 4.0ns ------ 250Mhz
    36 --- 3.6ns ------ 275Mhz
    33 --- 3.3ns ------ 300Mhz
    28 --- 2.8ns ------ 350Mhz
    26 --- 2.6ns ------ 385Mhz
    25 --- 2.5ns ------ 400Mhz
    22 --- 2.2ns ------ 450Mhz
    20 --- 2.0ns ------ 500Mhz
    18 --- 1.8ns ------ 550Mhz
    16 --- 1.6ns ------ 600Mhz
    14 --- 1.4ns ------ 700Mhz
    12 --- 1.2ns ------ 800Mhz
    11 --- 1.1ns ------ 900Mhz
    N0 --- 1.0ns ------ 1.0Ghz
    N1 --- 0.9ns ------ 1.1Ghz
    N2 --- 0.8ns ------ 1.2Ghz
    N3 --- 0.77ns ----- 1.3Ghz
    N4 --- 0.71ns ----- 1.4Ghz
    N5 --- 0.66ns ----- 1.5Ghz
    N6 --- 0.62ns ----- 1.6Ghz
    N7 --- 0.57ns ----- 1.75Ghz
    N8 --- 0.56ns ----- 1.8Ghz
    T0 --- 0.5ns ------ 2.0Ghz
    T1 --- 0.444ns ---- 2.25Ghz
    T2 --- 0.4ns ------ 2.5Ghz
    T3 --- 0.363ns ---- 2.75Ghz
    R0 --- 0.333ns ---- 3.0Ghz
    R1 --- 0.30ns ---- 3.25Ghz
    R2 --- 0.28ns ---- 3.5Ghz

    Code - Access time - Frequency for Qimonda GDDR (Qimonda went bankrupt at the beginning of 2009)
    GDDR2/GDDR3
    28 --- 2.8ns------ 350Mhz
    25 --- 2.5ns ------ 400Mhz
    20 --- 2.0ns ------ 500Mhz
    16 --- 1.6ns ------ 600Mhz
    14 --- 1.4ns ------ 700Mhz
    12 --- 1.25ns ----- 800Mhz
    11 --- 1.1ns ------ 900Mhz
    10 --- 1.0ns ------ 1000Mhz
    8 --- 0.8ns ------ 1200Mhz
    GDDR5
    32 --- 1.2ns------ 800Mhz
    36 --- 1.1ns------ 900Mhz
    40 --- 1.0ns------ 1000Mhz
    45 --- 0.9ns------ 1125Mhz
    50 --- 0.8ns------ 1250Mhz


    Examples :


    The memory of a Radeon 6970M:

    [​IMG]

    The memory of 9800M GTX from a Clevo D900C/M570TU :

    [​IMG]


    The memory of a 8800M GTX from a Clevo D900C:

    [​IMG]

    The memory of a GT 425M MXM card (ASRock) - this is where Hynix writes its timings on more recent GDDR:

    [​IMG]

    The memory of 8600M GS/GT GDDR2 (MXM types):

    [​IMG][​IMG]

    The memory of a 7800 Go:

    [​IMG]

    Other cards:
    ATI M4570: Laptop Forums and Notebook Computer Discussion (thanx to kiwitheiwik)

    Why in the end the video card manufacture decides to use other frequencies than the ones specified by the memory manufacturer I have no idea... But I guess that this can give a helping hand in having a successful overclock of the memories.

    Known GDDR frequencies:

    If you have other pictures of GDDR memories would be great.
    CardBrandTimingFrequencySupplier
    Nvidia 680MMXM Type 3.0b/ ? 041250 Mhz (x2)Samsung
    Radeon 7970MMXM Type 3.0b/ ? 041250 Mhz (x2)Hynix
    Radeon 6970MMXM Type 3.0b/ ? 041250 Mhz (x2)Hynix
    GTX 470MMXM Type 3.0b/Clevo W860/870/x7200 041250 Mhz (x2)Samsung
    GTX 460MMXM Type 3.0b/Alienware 041250 Mhz (x2)Samsung
    ATI M5870MXM Type 3.0b/Clevo W860/870 041250 Mhz (x2)Samsung
    ATI M5870MXM Type 3.0b/MSI GX740 051000 Mhz (x2)Samsung
    GTX 285MMXM Type III /Clevo 1A1000 MhzSamsung
    GTX 280MMXM Type III /Clevo 1A1000 MhzSamsung
    GTX 260MMXM Type III /Clevo 1A1000 MhzSamsung
    Quadro FX 3700MMXM Type III /Clevo/early Lenovo/early HP 11900 MhzQimonda
    Quadro FX 3700MMXM Type III /later Lenovo/later HP 12800 MhzSamsung
    9800M GTXMXM Type III /Clevo 1A1000 MhzSamsung
    9800M GTXMXM Type III /Clevo - D900C 12800 MhzSamsung
    8800M GTX MXM Type III/Clevo 11 900 Mhz Hynix
    9800M GTSMXM Type III /Clevo 12800 MhzSamsung
    9600M GTMXM Type II/Clevo/Acer12 800 Mhz Samsung
    ATI M 4670 MXM Type II/Acer 20 500 MhzHynix
    8600M GS/GT DDR2 MXM Type II 25 400 MhzHynix
    7800 GoClevo M59K 16625 MhzSamsung
     
    Last edited: May 16, 2015
    Vasudev and jaug1337 like this.
  2. Megacharge

    Megacharge Custom User Title

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    Nice guide, thanks for the response in the other thread and thanks for this guide as well, +rep.
     
  3. emike09

    emike09 Overclocking Champion

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    Excellent guide. This is the stuff I like to see. Repped.
     
  4. Blacky

    Blacky Notebook Prophet

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    I updated the post with the 8800M GTX memory frequency.
     
  5. xor01

    xor01 Notebook Deity

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    thank you blacky :D
     
  6. Soviet Sunrise

    Soviet Sunrise Notebook Prophet

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    Now here's something worthy of a bookmark.
     
  7. Blacky

    Blacky Notebook Prophet

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    Last weekend I've check the memories of my video card and they are also 1A. I assume that all Clevo 9800M GTX ran with 1A timing as in 1 Ghz.

    I've also got the chance to check out an 9600M GT from a Clevo M860 and it has 12 timings that 800 Mhz. The stock frequency for the 9600M GT so there isn't so much room for overclocking.
    So I've updated the first post accordingly.

    I've also found out something else but I will put that in a new thread.
     
  8. Blacky

    Blacky Notebook Prophet

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    Updated first post with new info on Hynix memories and some older 8600M cards.
     
  9. GanGstaOne

    GanGstaOne Notebook Evangelist

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    Very nice blacky :)
     
  10. TehSuigi

    TehSuigi Notebook Virtuoso

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    Dang - now I wish my memory chips weren't covered by thermal pads - I'd love to find out exactly how fast my DDR2 VRAM is spec'd to go.
    EDIT: Managed to find a pic of ONE 9500M GS MXM-II card over at LV2Go - definite Hynix memory, but the code's obscured by the camera angle. Looks like either 22 or 21 ns. No confirmation, though.
     
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