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Need help about Crossfire and Power Supply

Discussion in 'AMD / ATI' started by Qed, Jan 10, 2011.

  1. Qed New Member

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    Hello,

    I have a 2x HD6950, default bios, in crossfire configuration on an X58 MB and an i7 920. I tested the card separately and each card is able to reach gpu 880MHz and ram 1325 MHz (i didnt go further). My power supply is a 650W efficency 80+. Drivers installed are the latest at the moment i'm writing (10.12a). Everything at stock speed/settings.

    Problem:
    I have some "Drivers stop responding" in crossfire configuration when i run 3d applications. I assume this is related to the Wattage of psu. Windows is working without any problem in Aero.
    It's even more strange that i was able to run 1 complete benchmark run in 3dmark11, then i rebooted and started the problem, crossfire was on (P7800 score).

    The TDP of a HD6950 is 200W, i set the Power Control, for each card, at -20% so it should be around 160W, an i7 920 has 130W TDP (benchmark and games cant reach that cpu usage). The total TDP is 450W and TPD means maximum amount of power (even 99% load doesnt necessarily mean the aximum power absorbed).

    Since my PSU is 650W and the TDP is 450W i assume i have about 200W free for the motherboard (50W?), 1 hard drive (30W), 1 cpu cooler fan, usb mouse and keyboard. I'm start thinking i got scammed with the PSU...


    I will be able to replace my PSU in 20 days after i move (my luggage is already too heavy for the flight company) but the RMA will be a pain from my new location. Having a look around i found some ppl reporting the same behave of my cards/drivers in crossfire with 1000W PSU.
    Anyone else having this kind of problems?

    Thanks.
     
  2. Red_Machine

    Red_Machine

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    What brand and model is your PSU? Also, if you could fill out your system specs in the control panel, that'd be great.
     
  3. Qed New Member

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    It's an Lc-Power, i have 3 of these spread on my other PCs :)

    My complete system is (i hope this is what you asked me):

    Intel i7 920
    Gigabyte GA-Ex58-UD5
    3x2GB Corsair Dominator 1600
    Seagate Barracuda 1,5 TB
    Windows 7 64bit
    and the 2 video cards of doom :)

    Thanks for the reply.
     
  4. Red_Machine

    Red_Machine

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    I actually meant for you to go here and fill it out:

    techPowerUp! Forums

    Make sure you set it to show from the drop-down menu at the top right.

    I've never heard of LC-Power, but it appears that their website has been taken down by their host. Never a good sign...
     
  5. digibucc

    digibucc

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    why do you assume it's the psu?

    do you have ANY issues with just one card?
     
  6. Qed New Member

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    I had 1 card for few days running at 840MHz and stock ram frequency without any problem, did some 3dmark11 runs @ 880/1325 MHz, Bad Company 2 and alien vs predator.
    The second card just ran some 3dmark11 at 880/1325 MHz, i wanted to be sure the card was working and I set is as primary atm so that's the one i'm using with no issues.

    EDIT: I hope it's a driver problem even if i drivers sweep and installed back with no luck :-(
     
  7. Over50 New Member

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    Your system appear capable ... PSU could be an slight issue.

    The HD 6950, 6970 Drivers work with some things and not others. Many Bugs to work out.

    I have a MSI R6870 Twin Frozr II Radeon HD 6870 1GB 256-bit GDDR5 and I cannot find consistant Driver reliability.
    AMD/ATI have there hands full ... hopefully to be resolved in the next few months. The sooner the better. BTW: nothing wrong with getting a new Power Supply ..if ya have the money.

    Check each card separately in same slot ... then attempt CF again.
    Some folks go into Safe Mode ..Uninstall Drivers, use Driver Sweeper and Ccleaner , delete contents inside the Prefetch folder ... then re-install the new drivers.
    Before installing whole Catalyst package ..get individual DL for Drivers only.

    Eventually there will be a proper fix for all these inconvienent headaches. A driver that actually Works for starters.
     
  8. Qed New Member

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    It isn't the PSU. I removed the Application profile 10.12 (latest) and i can run at full power 3dmark2011 without any problem. The grapic score, 8600, shows that crossfire is fully working and taking advantage of the 2 cards.

    Games are the problem, most are only using only 1 GPU. In Bad Company 2 if i press ALT+Enter to swith from windowed to full screen i'm always getting a crash.
     

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