Strange Sapphire HD3850

Discussion in 'Videocards - AMD Radeon' started by bobhe, Dec 7, 2008.

  1. bobhe

    bobhe New Member

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    HD3850 512mb Crossfire
    I've just upgraded to a sapphire HD3850 from a HD2400. I bought it new in China and took it to the UK.

    I've noticed something very strange about it though. It runs stock at 750mhz core and 900mhz memory, much higher than the reference speeds of 668mhz and 825mhz that it should have. I've also tried overclocking and it reached 830mhz core and 1000mhz memory and played several hours of Crysis without any artifacts and issues.

    The card is Sapphire, BLUE PCB with a different cooler to the red single slot reference design.)

    Does anyone else know of similar crazy 3850s which run much faster than even a 3870!

    (How do I insert a photo of the card into a post?)
     
    Last edited: Dec 7, 2008
  2. scatman839

    scatman839 Ancient Guru

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    You have to upload an image to a host before sharing it, look at imageshack.
     
  3. DSK

    DSK Banned

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    http://www.ixbt.com/video3/images/sapphire-16/sapphire-3850-front.jpg

    is that what you mean ?
     
  4. spirits247

    spirits247 Member

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    The cards usually reach those speeds (750/1000) quite easily.

    It sounds odd that the speeds were higher by default though - perhaps the bios was altered or it's a special pre-overclocked version??
     

  5. mark501

    mark501 Master Guru

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    Sounds a lot like a Sapphire HD3870 GDDR3, which is the one I have. A single slot blue cooler and a blue pcb
    http://www.sapphiretech.com/us/products/products_overview.php?gpid=242&grp=3

    Its a little bit slower than the regular 3870, with GDDR3 memory clocked at 900MHz (1800MHz) instead of the usual GDDR4 memory at 1125MHz (2250MHz ) and the core at 766MHz rather than 775MHz.
     
  6. bobhe

    bobhe New Member

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  7. mark501

    mark501 Master Guru

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  8. bobhe

    bobhe New Member

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    The only difference with the cooler is the sticker. It's as if they ran out of 3870 chips to put on the pcb so shoved a 3850 on instead, but forgot to change the BIOS to clock it down to 3850 speeds.
     
  9. mark501

    mark501 Master Guru

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    I think 3850 and 3870 gpus are identical. And the only difference is 3870s higher gpu speed + faster GDDR4 memory (except for some slower versions with GDDR3 memory like mine)

    So my Sapphire 3870 could just as well be called "Sapphire HD3850 Super overclocked" or something. And the same could be said about your strange 3850 :)
     
  10. Darren Hodgson

    Darren Hodgson Ancient Guru

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    My own Sapphire HD 3850 AGP overclocks to 709/939 from 669/829 using the auto-overclock in the Catalyst Control Centre's Overdrive. It even passes the manual test at 720/950 which are the maximum and I was able to run the ATI Ruby Double Cross demo on loop with 4X AA at 1680x1050 for several hours while I watched a movie with no apparent issues or artifacts. Temperatures didn't seem to go above 75 C either.

    Should I be able to overclock it further? If so then how do I go beyond the limits set by the CCC's Overdrive feature?
     

  11. enoch

    enoch Banned

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    My powercolor 3850 goes to 770/950 with ati overdrive auto-tune.I haven't tested games yet because the settings don't seem to be sticking.Maybe I can test them with ati tool?
     
    Last edited: Dec 9, 2008
  12. bobhe

    bobhe New Member

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    You might be able to use Rivatuner, although I've not tried it on AGP cards before so I don't know. One issue I found with Rivatuner is that it seems to disable ATI Powerplay which makes the card run much hotter at idle.
     
  13. 3dsage

    3dsage Master Guru

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    Have you tried using the amd gpu clock tool.
     

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