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Topic: HD6xxx memory underclocking to 300mhz possible? (Read 1356 times)

legendary
Activity: 812
Merit: 1002
i used trixx on my 5870 i would hope haploid is using that or MSI afterburner
yes, ALL the HD5xxx cards works fine when underclocking the memory, but NONE of the 6xxx cards can get to the 300mhz memory range. i used MSI afterburner for both series
full member
Activity: 196
Merit: 100
when i set the memory clocks to like 200-300mhz, the memory settings don't "stick" and just reverts back

Take with a grain of salt, I mine in linux and haven't tried any of the Windows OC tools.

My experience is that the 6xxx series cannot underclock the memory further than CPU clock minus 125mhz in software.  Attempting to do so will set the 'peaks' properly, but the card simply reverts to the default memory clock. 

I run mine at 885 GPU / 760 RAM for example, and can't push the memory clock any lower with software.

I believe a BIOS flash should allow underclocking the memory further. I attempted this but stopped after a failed attempt when I was short on time.  I set the default clocks to 885/300, it seemed to boot fine, but got immediate BSOD rebooting into to Windows.  This indicates to me that a) the flash probably worked fine, and b) ATI drivers in Windows took a dump upon seeing the weird out-of-spec clocks.  I didn't have time then (or now unfortunately) to see if the linux drivers would accept the new clocks.

Perhaps someone with experience flashing alternate clocks / voltages to 6xxx series cards can chime in?
sr. member
Activity: 462
Merit: 250
It's all about the game, and how you play it
i used trixx on my 5870 i would hope haploid is using that or MSI afterburner
sr. member
Activity: 413
Merit: 250
What are you using to underclock it?
sr. member
Activity: 462
Merit: 250
It's all about the game, and how you play it
every card is different even though the 58xx cards are known to run at 300mhz memory my 5870 balks at anything less than 400 and is much more stable at 500.
legendary
Activity: 812
Merit: 1002
i have a HD6570 and i get almost 100mhash/s out of it after overclocking. however when i set the memory clocks to like 200-300mhz, the memory settings don't "stick" and just reverts back. i had this same experience with the 6950 i use to have. is this one of the characteristics of the HD6000 series? or am i doing something wrong?
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