ATI 3850/3870 Voltmod thread

[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.

[Factotum]

You tested it?

YES!!! It's work!!!

[Factotum]

ohhh, my pictures wrong. R1270 don't remove - remove end replace R640 (bottom C657) I correct it now in my post with pictures. Sorry
I'm remove R605&R615 and replace R640&R604 resistors to 330kOhms and get 1.34V in 2-D and 1.4 in 3-D on trimer 100Kohms. Trimer set to 47kOhms - 1.46V in 3D and 1.4V in 2-D

[Eldonko]

Awesome, pictures please! I may do it myself.

Did you actually remove those resistors or just bridge them with 300kohm?

[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.

[Ertu]

I need some help
Before i solder anything and make it really bad :P
I've got 2 Saphirre HD3870 Ultimate (blue PCB)
Where should i solder my VR for VGPU mod ?
Here is the picture



Thxs a lot for the amazing job you have done here !

[Gir92]

I'm a bit tired and don't want to read all the pages lol. Can someone tell me if there are any software programs that you can up voltages with? I remember using ati tool with my x1950xt to do so.

[Eldonko]

6 posts up.

You cant increase voltage via software, closest you can do is flash a BIOS with a touch more voltage if you can find one.

[a1k]

ASUS EAH 3850 TOP on air, vgpu 1.62v vddr stock :

#3 @ 2006 @ hwbot.org -> 14648 Points


http://www.hwbot.org/result.do?resultId=742047



#5 @ 2003 @ hwbot.org -> 45332 Points


http://www.hwbot.org/result.do?resultId=742049

[Clint]

ASUS EAH 3850 TOP on air, vgpu 1.62v vddr stock :

#3 @ 2006 @ hwbot.org -> 14648 Points


http://www.hwbot.org/result.do?resultId=742047



#5 @ 2003 @ hwbot.org -> 45332 Points


http://www.hwbot.org/result.do?resultId=742049

With 1.62 volt on air, what are your temps on that card?

With 1.5v under a modified Arctic Cooling Xtreme 2900 I get 1GHz on the core, and a load temp not exceeding 48C. I was a bit concerned pumping more than 1.6 volts into it, maybe I could give more considering the temps?

[a1k]

Temp around 75/80°c, room around 30°c .. (because of my SS...)
my SS is runing near the comp

really cold temp in Sweden you have

[Clint]

Temp around 75/80°c, room around 30°c .. (because of my SS...)
my SS is runing near the comp

really cold temp in Sweden you have

Cold?, I wish!
We do actually have a heatvawe in Sweden for the moment..
It's around 30°C here in my room too, very hot for the time of the year.

If you get 75-80°C giving 1.62v I guess I could feed my card at least 1.65v.
I will try it later tonight.

[ownage]

With 1.62 volt on air, what are your temps on that card?

With 1.5v under a modified Arctic Cooling Xtreme 2900 I get 1GHz on the core, and a load temp not exceeding 48C. I was a bit concerned pumping more than 1.6 volts into it, maybe I could give more considering the temps?

Hmm, isn't 13,5k low for 1ghz core? SM2 and SM3 seems low.

[lowtcell]

Hmm, isn't 13,5k low for 1ghz core? SM2 and SM3 seems low.

Yep, seems low, especially for a quad. I hit 12,400 with 850mhz and a dual core.

[a1k]

Because he have only 873Mhz on memory...
I think theses scores are correct...

PS : 900 default clock, and 873Mhz set?! why? you flashed the card with wrong frequency?

[Clint]

Because he have only 873Mhz on memory...
I think theses scores are correct...

PS : 900 default clock, and 873Mhz set?! why? you flashed the card with wrong frequency?

Yup, they are correct...I don't care that much about cheating

The memfrequency is lower because I flashed the Gigabyte card with a Gecube bios that was unlocked. I edited the bios to default 850MHz but GPU-Z still shows the factoryclock. The Gigabyte 3850 have Hynix 1.4ns chips, and Gecube have Hynix 1.1ns chips but it works perfect.

[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.

[DINGO]

would any one have a dead card with an RT9619A chip on it they would like to part with? if so please PM me and we could work something out

[quake6]

Does anyone know vmem for sapphire blue PCB?
http://www.techpowerup.com/img/08-02-23/3870_toxic.jpg

[TheKarmakazi]

With 1.62 volt on air, what are your temps on that card?

With 1.5v under a modified Arctic Cooling Xtreme 2900 I get 1GHz on the core, and a load temp not exceeding 48C. I was a bit concerned pumping more than 1.6 volts into it, maybe I could give more considering the temps?

trying upping your memory frequency should improve your score greatly.

[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