ATI 3850/3870 Voltmod thread

[Eldonko]

whitepaper pdf for that PWM. Can we see the rest of the card?

[OneyedK]

whitepaper pdf for that PWM. Can we see the rest of the card?

Yup, found it, a 100k variable resistor from pin 4 to ground should do the trick.

Rest of the card:
front

back

[Eldonko]

Can you follow the trace from pin 4 (FB) to the resistors or contact points? Not so easy to mod direct to PWM.

[OneyedK]

Can you follow the trace from pin 4 (FB) to the resistors or contact points? Not so easy to mod direct to PWM.

Yes, there is one open place to solder to.

I think the regulator for vmem is RT8105 but I can't seem to find a datasheet.

[Mungri]

Hi.

Can anyone point me out to a guide for increasing my 3850 voltages using software?

It would be apreciated.

Also ATI tool isnt detecting my graphics cards, I have the latest beta version and it doesnt detect them. And if anyone knows how I can overclock my second card beyond what CCC allows, it would be appreciated. Thanks.

[Eldonko]

try a different version of atitool, 0.26 is usually the best. If it wont work use rivatuner. You cant increase voltage via software, closest you can do is flash a BIOS with a touch more voltage if you can find one.

[Mungri]

try a different version of atitool, 0.26 is usually the best. If it wont work use rivatuner. You cant increase voltage via software, closest you can do is flash a BIOS with a touch more voltage if you can find one.

Thanks. Please see my thread on bios modding to the GDDR3 Gigabyte 3870 and help me out if you can.

[TheKarmakazi]

Hi.

Can anyone point me out to a guide for increasing my 3850 voltages using software?

It would be apreciated.

Also ATI tool isnt detecting my graphics cards, I have the latest beta version and it doesnt detect them. And if anyone knows how I can overclock my second card beyond what CCC allows, it would be appreciated. Thanks.

AFAIK software volt mods dont really work.

You can use rivatuner, gotta have 2 monitors (extended desktop - 1 monitor for each card). CF disabled. Then riva works to OC both separately. Then go into CCC enable CF. Disable extended desktop, and BOOM your done

[wittekakker]

Yes, there is one open place to solder to.

I think the regulator for vmem is RT8105 but I can't seem to find a datasheet.

RT8802 for GPU core. Tried soldering directly to the chip, not working. Didn't found any resistor configs either.