ATI 4870X2 voltmod thread

[C-N]

Sorry guys, Had a big holiday weekend here in the U.S. I looked everything over again and all i can suggest is checking resistance of this point to check it.

Sorry I didn’t reply to this earlier but my XS notifications have been patchy if at all recently. No Resistance to ground, no Continuity to pin 9.

[spl]

wich is the vgpu mod??

[C-N]

wich is the vgpu mod??

This one http://www.xtremesystems.org/forums/...7&postcount=41

50 ohm pot between pin 9 & ground

CN

[spl]

but this guy use a pair of 500ohm!!1mohm?
o 50ohm??
but this is for one core or 2 core ??
sorry
spl

[CCC]

use any vr from 50ohm to 500ohm the lower '50ohm' the better as you can tune in better since stock resistance is 3ohms or so

and btw if you join any two legs of the ic you can short the card even if the power is off if power is left charged in the caps

so if you have a great card/s and cant rma or afford to kill a card at '$559' the odds of this mod going wrong are very very high

[HighT3ch]

from mouse
[I]for gpu#2 you have a solder pad point on the backside as stated in the guide at XS

Can you please specify/show which point is that, as I am somewhat confused?

[C-N]

Can you please specify/show which point is that, as I am somewhat confused?

Top picture post 32

[spl]

This one http://www.xtremesystems.org/forums/...7&postcount=41

50 ohm pot between pin 9 & ground

CN

but this guy use a pair of 500ohm!!1mohm?
o 50ohm??
but this is for one core or 2 core ??
there are two different vmod?
sorry
spl

[CCC]

yes there are TWO gpus each needs its own voltage mod

gpu #2 towards the back of the card has a solder pad that conects to pIN#9 on the back of the card easy access easy soldering

gpu#1 has no solder pad so you have to solder directly to the leg of the vreg pin #9

you can use a 20ohm to a 1k vr, lol but anyhting over 50ohm is asking for trouble some guys use what they have casue well thats all they have/had at the time

so 2 mod
for 2 gpus
and use 2 50ohms multi turn vr's

[HighT3ch]

CCC can you please give me a resistance value (measured on the vr after you disconnect it from the circuit) to use as an estimate, as I use fixed resistors - I avoid vrs at all costs.

[T_M]

spl, sounds like you havent done enough research to be attempting a voltmod on an expensive card.
might i suggest you learn about common volt mods before ruining your 4870x2

[r1rhyder]

Great suggestion.

[cowie]

any air results?....the card goes 860 stock for me now..

[C-N]

any air results?....the card goes 860 stock for me now..

I get about 21500 in 3DMARK06 & 13500 in Vantage with my DFI P35 sig rig using Vista 32 bit running the 4870x2 @ 825/1050mhz.

I can run 860 or so on the core but my 06 & vantage scores actually go down what are you making on your DFI P35 & E8500?

CN

[cowie]

not too well 31500 o5 stock clocks and about 90k 03 840/1000
now i put e8600 back in,and i sent card back to newegg for refund.

[T_M]

First card modded, bought a new superfine tip for my iron just for this .
My default resistance was 3.1 Ohms so i used 100 Ohm VRs.



And now to test it



Great suxses!
Now for the second card.....

[Gautam]

Damn...that takes balls Tim, I didn't expect anyone to actually try soldering right to the IC leg. I was planning on gooping the whole area with glue gun and praying for the best myself.

[T_M]

Has anyone thought of exposing and connecting to the trace on the PCB that comes from that IC leg?

[CCC]

nice work TM>

both my cards are also now soldered. all ya need is a steady hand a good iron and good light and its not that hard at all

nice work

[T_M]

The hardest step is to get a small dob of solder onto that IC leg and draw it out to give something a bit nicer to connect the wire to.
After that yeah a piece of cake.

[T_M]

Here's one modded card rekitted for hardcore air testing:

[emertX]

any air results?....the card goes 860 stock for me now..

How did you reach thi freq on both cores?
In CCC it isn't possible.
How could you manage the freq and the fan together?

[T_M]

emertX, those clocks speeds are possible by flashing to the Asus TOP bios (see other thread).
You can manage the fans/clock in a variety of ways, BIOS / CCC / Rivatuner / AMDGPUClockTool / etc.

[emertX]

Thank you!

Is it enough to flash the original asus top bios? Or do I have to flash yours?

[cowie]

How did you reach thi freq on both cores?
In CCC it isn't possible.
How could you manage the freq and the fan together?

no flashing just amd tool and riva for fan...only one card