ATI 3850/3870 Voltmod thread

Quote:

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Originally Posted by STEvil

To keep from shorting the GPU voltmod you guys might also want to look at putting a fixed resistor in series with the VR... I would say a 10K fixed should do for most but it might be a bit high for getting 1.6v+...

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Ok so with the VR soldered to the two points, where would the resistor fix into place?


Also, someone take some pics of the mod, dont be greedy! :D

See my pics on the previous page.

The resistor would be in series with one leg of the pot.

ie: solder point-> resistor-> leg of pot

Can someone share with us what Values of resistance equate to vgpu values?

I like toe hard wire w/o a POT. strait resistors ;-) But I'd like to use a smaller POT also. Everyone says 100kohm, but what do you end up at to achieve 1.5vgpu? 15k? 50k? if so I'll buy a 50kohm.
I haven't hard modded since my 9600Pro. Will be fun to volt and watercool again.

1kgpu on water and 1.5-1.6vgpu sounds like fun.

3850 is here... give me a few days to mess with her then hardmod here we come!!!!!!!!!!! and chiller !!! ! !!:yepp: :yepp: :cool: :rolleyes: :D

can someone post some real benchmarks of the overclocked 3870?

like crysis 1280x1024 with EVERYTHING maxed out, etc,

thanks

i can tell you that i run crysis at 1650x1080 with High Everything with a couple of settings Very High.

Though not really any use cause games arnt just dependent on ur gfx card. See my specs below.

hardmod confirmed to work on the 3850. the stock 3850 volts are 1.22v 100k VR got it to 1.28 im at 1.3 816mhz core and still testing... :D :D :D

I believe my specs below are the most generic for today's setups and my comp should do the crysis bench.

All i need is a photographic diagram of the completed mod and I can get the mod done in less than 30 mins.

I know for sure that 1650x1050 crysis everything high at 877/2600 i get a good 20-30fps or lower.

x2 3800 @ 3.0
Crucial Ballistix ddr500
msi 3850 823mhz/945mhz

9733 3d06- http://service.futuremark.com/compare?3dm06=4047261

im happy so far... 10k is my goal..:yepp: :yepp:

edit: 3d06 9889
850/999 1.44v http://service.futuremark.com/compare?3dm06=4047847

ive done the mod but i dont know why every time i set the core clock above 860 it will hang?ive set the vgpu at 1,5 1,4 doesent make any difference?

and if i set the core clock directly at 900 or above the core clock reading show me 34Mhz at riva tuner??very strange???

any one can help?

Quote:

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Originally Posted by R*r

ive done the mod but i dont know why every time i set the core clock above 860 it will hang?ive set the vgpu at 1,5 1,4 doesent make any difference?

and if i set the core clock directly at 900 or above the core clock reading show me 34Mhz at riva tuner??very strange???

any one can help?

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try the modified bios.

thanks man,now im benching @ 1G :up:

i wish the bios fixed the 3850s 860 mhz lock.... :shakes: :shakes: :shakes:

Guys, what's a good up-to-date utility to edit an ATi BIOS file?

RadEdit, and RaBiT are way too old right now, will NiBiToR work, or is it only for nVidia BIOS'.

Thanks.

thank's guys worked like a charm but i had to go 1,5 for a stable 945mhz
next step is to reseat my wb but i'm waiting til i'm adding a new card hafto rebuild my loop then anyway

any fix to get crosfire oc higer yet?

http://www.radioshack.com/product/in...entPage=family

what do you guys think of this potentiometer for the voltmod on the 3870?

Has thee been any confirmed ideal voltage for the VDDR mod? and What VR-size/resistance should this POT have?
I haven't done hardmod since the 9800 and X800 time, so it's been a while :D
For the moment im only doing 900mhz on the core. Boring stockcooler soon goes off.

For the cooling later on i'll be using a triple-radiator + 6x 120 fans for my new MCW60's. Cpu,Nb+Sb will go off with the same cooling. For the moment not really finished with my project. So cooling shouldn't be any problem.

Quote:

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Originally Posted by SNiiPE_DoGG

http://www.radioshack.com/product/in...entPage=family

what do you guys think of this potentiometer for the voltmod on the 3870?

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It would work but personally, I'd use a multiturn VR.
Single turn pots like that are very inaccurate for vmodding.

Quote:

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Originally Posted by largon

It would work but personally, I'd use a multiturn VR.
Single turn pots like that are very inaccurate for vmodding.

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ty very much, im off to radio shack!

finally broke 10k with my x2 3800 - 3850 850mhz/999mhz yahooooooo :D

http://service.futuremark.com/compare?3dm06=4075418

Quote:

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Originally Posted by JamesBong420

finally broke 10k with my x2 3800 - 3850 850mhz/999mhz yahooooooo :D

http://service.futuremark.com/compare?3dm06=4075418

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Gratz :up:

Quote:

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Originally Posted by JamesBong420

finally broke 10k with my x2 3800 - 3850 850mhz/999mhz yahooooooo :D

http://service.futuremark.com/compare?3dm06=4075418

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Now go for 11k :D:up:

Any differences between HD3870 and Vmodded? Since the Vmodded bioses dont work :/

Nvm: I saw some results on page 3 WTF! I want a 2nd watercooling loop!! :p

finally can touch 15k :D
http://service.futuremark.com/compare?3dm06=4087007

http://cgi.ebay.com/ws/eBayISAPI.dll...ksid=p3907.m29

i got one of these pots for my mod, opinions?