Visiontek HD3870 OC voltmod possibilties?

[Verizon]

Bestbuy had a sale on 3870s sunday and iv been playing with it, im getting 3dmark scores of 9677 and what not, but i want to voltmod it to get it over the 915MHz core that it is stuck at. however upon researching the voltmod and inspecting the card, i found i dont even have a resistor in place. this card has the sdame layout, traces and most of the electronics in the same place. i was wondering about a solution.
here is a picture of the back of my card.

http://img.techpowerup.org/080603/P5210074865.gif

[FR@NK]

Mine also max out just past 900 on the core with stock voltage...but i think its the temps that are holding me back, not the voltage. When I get off work I'll see if mine is missing that same resistor.

[philbrown23]

you could hardmod it, that pencil mod is only good for slight increases

[Solaris17]

well if all you had to do was pancil over that resistor and now its not their just pul solder on it and connect the bridges.

[Verizon]

you could hardmod it, that pencil mod is only good for slight increases

i only want to slightly increase it until i get a good soldering iron. the soldering iron i have burns solder and it burnt the enamel of titanium or zinc of itself. so hardmod would probably destroy the card with that iron. :(

[sneekypeet]

well if all you had to do was pancil over that resistor and now its not their just pul solder on it and connect the bridges.

There was never a resisiter there from what I gathered...plus wouldnt soldering it createalmost no resistance, which will send his voltages through the roof and possibly damaging the card?

My vote if its a must to get more....try bios modding the voltage if possible. If that does not work you are in fact down to a hard mod with potentiometers!

[Verizon]

well if all you had to do was pancil over that resistor and now its not their just pul solder on it and connect the bridges.
i considered that. and in theory it might work, my worry is unlike the guide that random murderer made this card is missing all of the electronics that lead up to that resistor. so what if visiontek changed a few things and now theres more voltage in that trace then on other cards. then i could blow my card through the roof. im broke i just want to slowly pencil on some volts, in a sense.

[Solaris17]

it wouldnt necissarily bring it through the roof. it wouldnt only raise his voltage the maximum resistance that that resistor would have because their are resistors before and after that one in the cuircuit.

i considered that. and in theory it might work, my worry is unlike the guide that random murderer made this card is missing all of the electronics that lead up to that resistor. so what if visiontek changed a few things and now theres more voltage in that trace then on other cards. then i could blow my card through the roof. im broke i just want to slowly pencil on some volts, in a sense.


ahh i didnt know the resistors before that were gone aswell than the only thing left is to do what sneeky said and start doing it via bios or potentiometers.

[Verizon]

There was never a resisiter there from what I gathered...plus wouldnt soldering it createalmost no resistance, which will send his voltages through the roof and possibly damaging the card?

My vote if its a must to get more....try bios modding the voltage if possible. If that does not work you are in fact down to a hard mod with potentiometers!

how would i go about Bios Modding it? i am a noob when it come to bios software.

Hope your listening Nam o.0

[sneekypeet]

Well there are a few here that got really good at it. I only flashed mine to beat the 860ish Core lock.

cdawall did a nice write up on how to flash the HD3850 with more voltage...principle is the same really. Might even want to surf through Rqandom's Vmoding the HD3870's and see what info is in there for ya.

Warning on flashing( Winflash has more inherant risks than flashing in DOS with a usb or CD)

[Dr. Spankenstein]

There is always the "New Mod" option. You are basically creating a trench that the graphite will sit in (as opposed to sitting on top of the resistor".

Here is the post (http://forum.techpowerup.com/showpost.php?p=796965&postcount=886) with the info.

Make sure you have your DMM at the ready because with this method you coud be making close to a full bridge. You'll have to have a plan to remove the graphite if you shaded too much. trog100 siad he to use the DMM lead to slightly scratch away at the surplus graphite until the resistance/voltage is what you are comfortable with for the cooling solution you have.

[niko084]

I have different bios voltages sets from the factory and re-flashed mine for clock drop in 2d mode and a nice overclock in 3d mode.

I'm doing 1.258 I believe at 300/1200 2d mode and 1.3 volts at 950/1200 3d mode now and being stable, also reset my fan speeds.

[Verizon]

what is the standard file size for a 3870 bios file?

[Verizon]

so i just saved bios file, but the max voltage is 1.327 to edit. thats what mine ran before, so i dont want to flas yet because it wont be an upgrade.

[Solaris17]

post up the bios file ina zip so we can look at it.

[niko084]

so i just saved bios file, but the max voltage is 1.327 to edit. thats what mine ran before, so i dont want to flas yet because it wont be an upgrade.

Well I'm running 1.3 and at 950 I'm getting pretty warm, so really you probably will want some way better cooling before trying to go above 1.327.

[Verizon]

Well I'm running 1.3 and at 950 I'm getting pretty warm, so really you probably will want some way better cooling before trying to go above 1.327.

what temps do you run,
904/1198 49/50c idle, 57c full load with stress tester. is that to high? if thats to high then im glad i modded the cooling.

[Verizon]

post up the bios file ina zip so we can look at it.

here is the bios fresh from dos and atiflash

[Verizon]

this is what i just flashed onto my card, and so far so good

[Verizon]

no help. with the 1.327 voltage i still max at 915 though i am glad that the bios mod worked

[Verizon]

so theres no way to increase my cards voltage past 1.327? if i could get my 7600gt up to 1.67 volts im sure this one can go that high/ higher

[niko084]

so theres no way to increase my cards voltage past 1.327? if i could get my 7600gt up to 1.67 volts im sure this one can go that high/ higher

Doesn't work that way....

FYI- I'm running about 68c solid durring 3dmark, too warm to push further, I like em around 60c personally.

I run 24/7 clocks of 300/1200 and 900/1200 now, keeps me around 60-61c max temps.

[Verizon]

FYI- I'm running about 68c solid durring 3dmark, too warm to push further...

thats 10 c higher than my max, it may be the problem but i would like to doubt it if you run higher maybe my 12v rail isnt giving the card enough power or maybe the voltage is dropping from the load?

[niko084]

thats 10 c higher than my max, it may be the problem but i would like to doubt it if you run higher maybe my 12v rail isnt giving the card enough power or maybe the voltage is dropping from the load?

Its possible, but all cards vary a bit from card to card, and some cards run cooler/warmer than others and even report slightly differently, so the possibilities are endless.