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Title: HD 6850 Memory Clock Jumps to 1000Mhz Even Though Underclocked Post by: kernelpanic on August 05, 2011, 06:29:32 PM Running Afterburner on Win 7, 6850 set to 325 mhz (I tried other speeds as well) memory clock. When I start the associated miner, Afterburner shows the memory clock jumping to 1000mhz. I'm assuming this is not normal behavior (my other cards don't do it).
Is anyone familiar with this? Any suggestions? Title: Re: HD 6850 Memory Clock Jumps to 1000Mhz Even Though Underclocked Post by: bmgjet on August 06, 2011, 12:07:43 AM Rivatuner is the only one that will work properly to lower the memory clock. Going below 350mzh makes weird stuff happen if you try use the gpu for anything else (firefox).
Title: Re: HD 6850 Memory Clock Jumps to 1000Mhz Even Though Underclocked Post by: kernelpanic on September 08, 2011, 11:35:41 AM I finally resolved this issue, figured I would post the answer in case anyone else is still having the problem. Be sure your MSIAfterburner.cfg has the config below. I had everything below except my OverclockingMode set to 1. Once I switched it 2, the 6850 respected the Afterburner settings. I'm now running cool at 301mhz memory...
[ATIADLHAL] EnableUnofficialOverclocking = 1 UnofficialOverclockingEULA = I confirm that I am aware of unofficial overclocking limitations and fully understand that MSI will not provide me any support on it UnofficialOverclockingMode = 2 AccessibilityCheckingPeriod = 0 Title: Re: HD 6850 Memory Clock Jumps to 1000Mhz Even Though Underclocked Post by: CanaryInTheMine on September 09, 2011, 02:53:06 PM Rivatuner is the only one that will work properly to lower the memory clock. Going below 350mzh makes weird stuff happen if you try use the gpu for anything else (firefox). complete b.s. Title: Re: HD 6850 Memory Clock Jumps to 1000Mhz Even Though Underclocked Post by: cicada on September 13, 2011, 08:10:18 PM I'm having the same trouble (though memory clock jumps to 300) under Linux. Is there an aticonfig command I've missed out? I've enabled overdrive and set the peak memory clock to 300, but the utility reports that I'm running 1050. I've had this issue with every 6XXX series card I've used in Linux (Ubuntu 10.10). Using aticonfig I've never been able to set my XFX 1GB 6950s memory clocks less than 125mHz lower than the GPU clock. In order to set memory clocks outside of the default ranges at all, I have to use AMDOverdrivectrl to set the default clocks for each power state, but even those don't 'stick' - as soon as I 'push' the card the memory clock ramps up to max. The 6870 I picked up recently won't drop below 100mHz less the GPU clock. It seems to be the same issue as Windows boxen, but at least there the manufacturers have specific utilities to get around it. It also appears that it may be vendor/card version specific, as some people have had success underclocking mem on a handful of these cards in Linux. With the BTC prices so low and my power usage so high lately, I'm resorting to bios flashing a lower memory clock and voltages on all of these cards this weekend. Totally kills their use in Windows or for gaming (unless you flash them back), but will be worth it for mining - at this point I need to eek out every bit of efficiency I can in order to stay above water. Title: Re: HD 6850 Memory Clock Jumps to 1000Mhz Even Though Underclocked Post by: Raize on September 13, 2011, 09:49:01 PM I'd be very interested in what bios you are running on your 6870. I have tried flashing new bios to mine and bricked one.
Title: Re: HD 6850 Memory Clock Jumps to 1000Mhz Even Though Underclocked Post by: cicada on September 13, 2011, 10:02:20 PM I'd be very interested in what bios you are running on your 6870. I have tried flashing new bios to mine and bricked one. Just the stock bios at the moment, I haven't played with it yet. That one is my least concern really, it's nice and cool and doesn't draw a whole lot of power for it's 300mh/s, may just leave it ;) Title: Re: HD 6850 Memory Clock Jumps to 1000Mhz Even Though Underclocked Post by: haploid23 on September 13, 2011, 10:51:53 PM OP, you're not the only one. this is a very common problem for the 6xxx series cards. although some cards are lucky in that they can underclock memory fine, but majority has this memory underclocking limitation. refer to this thread:
https://bitcointalk.org/index.php?topic=31013.0 Title: Re: HD 6850 Memory Clock Jumps to 1000Mhz Even Though Underclocked Post by: CanaryInTheMine on September 15, 2011, 07:03:30 PM I'm having the same trouble (though memory clock jumps to 300) under Linux. Is there an aticonfig command I've missed out? I've enabled overdrive and set the peak memory clock to 300, but the utility reports that I'm running 1050. I've had this issue with every 6XXX series card I've used in Linux (Ubuntu 10.10). Using aticonfig I've never been able to set my XFX 1GB 6950s memory clocks less than 125mHz lower than the GPU clock. In order to set memory clocks outside of the default ranges at all, I have to use AMDOverdrivectrl to set the default clocks for each power state, but even those don't 'stick' - as soon as I 'push' the card the memory clock ramps up to max. The 6870 I picked up recently won't drop below 100mHz less the GPU clock. It seems to be the same issue as Windows boxen, but at least there the manufacturers have specific utilities to get around it. It also appears that it may be vendor/card version specific, as some people have had success underclocking mem on a handful of these cards in Linux. With the BTC prices so low and my power usage so high lately, I'm resorting to bios flashing a lower memory clock and voltages on all of these cards this weekend. Totally kills their use in Windows or for gaming (unless you flash them back), but will be worth it for mining - at this point I need to eek out every bit of efficiency I can in order to stay above water. https://bitcointalk.org/index.php?topic=35792 |