Overclocking CF 5850's Not going well.....

So finally got a second HD5850, everything works peachy at stock, loadsa frames, but me being me I just want more so I decided to do some slight overclocking. Now I know what my first HD5850 is capable of, it can do 1015/1200 with 1.225V. However I have no idea what my new ASUS HD5850 can do and unfortunately it would be very differcult to test it on its own as my first HD5850 is under water and would be a PITA to remove.... :non:

So I started off with both cards at 725/1000, then I decided to go for 775/1125 which I consider to be a small overclock and everything was good. So then I tried 825/1125 and this made unigene Heaven 2.1 crash straight away (I thought that was crap that a 5850 couldn't do 825 core :/ )

I then tried 815/1125 however this gave me artifacts, but didn't crash.

Next I tried my old 5850 at 725/1125 and my ASUS 5850 at 805/1125 which worked fine in kombuster. Then I loaded up MSI Afterburner put the core to 825 and left the Mem at 1000, upped the Vcore to 1150Mv (From the stock 1087Mv) loaded up Kombuster and still got artifacts :heink:

I then set everything back to default and still got artifacts when I tried 3DMark06! :pt1cable:



At this point I was like "OMG! I broke it! :ouch: "

However after a restart everything was fine at stock again.

So do I really have a HD5850 that can't do 825Mhz with 1150Mv ? Or am I doing something wrong? :whistle:

Oh forgot to mention that my ASUS CCC's overclocking limits are 1200Core and 1400Mem, and no I haven't flashed the BIOS. Is that normal ?
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More about overclocking 5850 well
  1. Both of your cards are ASUS, right? Direct CU? Voltage Control?

    What about the temps? Is it high enough?
  2. No there both reference cards, one is a Gigabyte and the other is an ASUS. As they are reference they both have voltage control (I assume)

    My gigabyte is under water so it never goes over 39C and the hottest I've seen the ASUS go is 71C under kombuster with Auto fan speed.
  3. Ok WTF is going on.... Now My gigabyte CCC limits have changed, the lowest I can set my Gigabyte card to is 820Mhz Core and 1000Mem.

    I'm seriously confused. I tried installing 10.6 and got a BSOD, reinstalled Cat 10.4 and the minimum limits are still 820/1000.

    When I had just the gigabyte card I modded its BIOS so that in 3D mode it would go to 1000/1200 1.225V and changed the CCC max limits to 1100/1300 but never changed the minimum limits.

    Anyone got any ideas please...?
  4. Thanks for enlightening me dipankar....
  5. Just tried to launch smart doc and got a BSOD, then tried to change some value's in MSI AB and got a BSOD.

    Any idea's people?
  6. Another update:

    I shut down the PC, disconnected the Crossfire bridge, and changed the monitor cable from the first card (The gigabyte one) to the new ASUS card, without the crossfire bridge I get no display at all (The PC still boots into windows fine).

    With the CF bridge connected and the cable in the ASUS card I do get a display, but only after windows has loaded.

    I always thought that the second card should still display even if there is a card in the first PCI-E lane. Can anyone clarify?
  7. Well Its easier said than done because to remove the first card from my PC I have to drain my entire loop (which is risky at the best of times) and it would take hours, then when I come to install it again I'll have to leak test the loop for 12+ hours.

    But... my step dad has a PC I could test the new card on, but he's not home for another 3 hours... :/

    Crossfire works fine at stock, and even with a small overclock (775/1200) But the ASUS one doesn't respond to voltage change and will nearly always Blue screen when I try and adjust anything outside of CCC.

    Any 5850's should work fine together, the only difference between the two cards are some stickers and a name badge.
  8. Are you sure the two cards arent conflicting with each other?
    its better to have two identical cards in crossfire.
    also two HD5850's in CF uses loads of power so maybe you dont have enough amps on the 12v rail.
    PS what are your PC specs?
  9. System spec's are:

    Core i7 920 @ 4Ghz
    Gigabyte GA EX58 UD5
    3 x 1GB OCZ 1333Mhz
    Corsair obsidian 800D
    Corsair HX850W
    Gigabyte HD5850
    ASUS HD5850
    Samsung Spinpoint F3 500GB
    DVD ROM Drive
    9 fans
    Custom Water loop for CPU and Gigabyte HD5850.
  10. Quote:
    if u crossfire works with stock speed.then ur cards are fine.as i told u that all card donot overclock the same.so just stop tweaking with it and start enjoying games.be happy with what u paid for.if ur asus card is not responding to overclock then stop overclocking becoz u can easily fry it.


    Yes but that doesn't explain the BSOD's and I think your wrong about the display thing because what about people that have more than one card in their PC so that they can run more monitors, the second card should still display even before its got to windows. Anyway I'll find out soon enough.
  11. Smart doc doesn't even fully load before it BSOD and I don't even hit apply in MSI AB and it BSOD's.

    The card should still display without a bridge, its not like it can only do crossfire, it should work fine on its own.

    Anyone know if the reference ASUS HD5850's CCC limits are mean't to be 1200/1400, I thought it should be 775/1125?
  12. dipankar its called buyers remorse

    Psycho I'll try it out and let you know how I get on.
  13. That didn't go well at all, That BIOS bricked my gigabyte card, had to drain my loop just so that I could swap the 2 cards around so that the new card is ion the first PCI-E lane which aloud me to flash to its orginal BIOS, but its still semi-f*****

    on its own it will display until it hits the windows loading bar and then it BSOD's, if I run in safe-mode it'll get into windows but ATI drivers can't detect the card.

    The ASUS one works fine if I plug the gigabyte one into the second PCI-E lane crossfire enables but I can't load anything 3D.

    Things are going from bad to worse.
  14. GPU-Z

    0Mhz Core and 0Mhz Mem

    No texture or pixel fill rate or bandwidth It (GPU-Z) just crashed....
  15. Rustyy117 said:
    Another update:

    I shut down the PC, disconnected the Crossfire bridge, and changed the monitor cable from the first card (The gigabyte one) to the new ASUS card, without the crossfire bridge I get no display at all (The PC still boots into windows fine).

    With the CF bridge connected and the cable in the ASUS card I do get a display, but only after windows has loaded.

    I always thought that the second card should still display even if there is a card in the first PCI-E lane. Can anyone clarify?


    The BIOS always tries to output to the first PCI-E lane (if there's a graphics card there) while Windows remembers you're settings.

    The 2nd card could be faulty, is the warranty intact?
  16. yeah learnt that the hard way :/

    Little update:

    Flashed the gigabyte card again from cypress.bin to cypress.bin (yes, the same exact BIOS) which fixed the card, I also reinstalled 10.4 and now 3D is working!

    So back to square one...

    I've had enough of CF already... maybe time for ebay. but deffinately time for bed.
  17. So does CF on stock clocks work now?
    Btw: do you have a thing for black & white pictures?
  18. I've only ran the heaven benchmark, but so far yes CF at stock works, I don't know if smarkDoc or MSI AB will still give me BSOD'd or not.

    My display picture for this forum is B&W because my gigabyte mobo has some horrible colours like pale orange and yellow, ruins the look alittle.

    And I'm drawing the girl on my desktop and its slightly easier if she's B&W.
  19. Dude.... like thats my wife...


    Nah, kidding I am, and yes I screwed up my PC again, do you know I've killed one HD5850 before buy removing it from my PC, I spilt water on another HD5850, and as you know I've bricked and then unbricked another HD5850. All In the pursuit of more frames :)

    Oh BTW the ASUS card is fine, and so is the Gigabyte card.


    EDIT: forgot to say, I don't have a clue what her name is. :P
  20. Yeah crossfire is working now.

    Your score is alittle low, I think my High score was 52xx, bare in mind that I got that score with a 4Ghz core i7 and my 5850 at 1000/1200.

    However I think the low present runs at something like 1024 x 768 or 1280 x 1024 so at that resolution your CPU may be bottlenecking your HD5850.



  21. **Sad face** I hate stock... :/
  22. Use afterburner my friend, try Overclocking each GPU independently, disable crossfire, and run a Folding@Home session on each GPU from 1 - 100%; Single best way to test an OC on GPUs independently. I achieved this with my 480s SLI.
  23. And that Benchmark Sucks for measuring actual performance. Use something like STALKER for a benchmark.
  24. Yeah that my low score with everything stock and crossfire diabled.

    @DarthPiggie, if I use Afterburner with 2 cards installed it bluescreens, so I have to take a card out to test for max OC's. I use unigene Heaven 2.1 benchmark for stress testing (Don't have F@H installed).

    Managed to get my ASUS card to 880 core and 1200 mem with 1.149V which isn't to bad. I'll see how much I can push it later with 1.250V (max voltage I'm willing to use for 24/7)
  25. It is really suspicious that the Afterburner would cause a BSOD. Hmmm...if I were you, I would flash the other card to the ASUS Bios for increased stability and compatability. You may even get better OCs as well.
  26. yeah it is strange, I might try flashing the gigabyte to an asus, but not now, I've had enough of flashing for awhile.
  27. ok got the asus bios from the new asus card via gpu-z, then modded the bios to 1000/1200/1.225v (which i know to be stable). Everything working A-ok!

    Did some benches with both cards at 870/1200, getting silly frame rates like Farcry 2 maxed noAA 1920 x 1080 minimum FPS of 106FPS and an average of 153FPS

    Crysis all very high 1920 x 1080 DX10 NoAA Min of 37FPS average of 59FPS

    BFBC2 nearly always above 100FPS all maxed 1xAA 16xAF 1920 x 1080.
  28. :lol: not this again.... I don't see a big enough visual difference to justify the performance drop so I use the lowest amount of AA (Unless I'm playing a game where it needs AA badly).

    Happy with the cards and the scaling (seems to be between 60-100%)

    I downloaded something to get openCL ticked but I can't remember what it was, just google it.
  29. The thing to get OpenCL is probably StreamSDK, which includes the OpenCL driver.
    How do you get 1xAA? The lowest I've ever seen is 2xAA.
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