GTX285 VGPU and OCP mod

[chispy]

[QUOTE=Mayk-Freak;3937528]I´ve done the GPU Volt Mod, results with 1,26 V watercooled.

Great to hear that it worked for you bro , i just came back from a boyscout jamboree i was with my little son , so now i have some spare time to test this volt mod , did you find the v.core meassuring points ?
Where exactly are you meassuring voltages for V.core bro ? Thanks in advanced.


chispy.

[Mayk-Freak]

my bro...look at the white arrow, there was my meassuring point from the gpu voltage...my new result is 1,29 V...the dimm-mod I haven´t done yet

[chispy]

my bro...look at the white arrow, there was my meassuring point from the gpu voltage...my new result is 1,29 V...the dimm-mod I haven´t done yet

Thanks m8 , i was poking around with my DMM on the card with power on and it short it , i know the mod works , wednesday my new card will be here and i will try again .


chispy.

[KingK76]

Hey guys I had to RMA my XFX card and in return I got one of these new PCB 1.1 models. After throwing a man style hissy fit I checked back here to see if there is a Vmod for this card (as I already have a EVGA SSC volt modded and waiting for it's brother to re-join it in Vmodded SLI bliss). Anyway I have looked over the last couple of posts but feel the directions for the mod are a little confusing. Look I was easily able to perform the last Vgpu and OCP mod but I have no formal skill or schooling for this type of thing and am having trouble following the directions (it doesn't help that they aren't in english). Anyway could someone please help me out as I really feel like crap now that I will either have to un-mod may other card or sell this one. I don't want to do either of those. BTW am I correct in that to perform this mod you have to solder to the tiny leg of the voltage chip?!

[KingK76]

Okay I may have gotten a little overwhelmed by one of the photos on the link to the vMod. I just took a look at Chispy's vMod and it seems that you solder the middle leg of a 100ohm VR to the 19th leg of the ISL6327 chip and the other leg of the VR to ground and then I would imagine have it turned up to 100ohm and then go down to raise vGPU. Is this correct? If so I will attempt this on the weekend when I have the time to perform such an operation (I have never soldered to anything that small before!). Anyway please let me know if this is correct and I can go ahead and let you guys know how it turned out. Thanks!

Oh and another quick question. Is there an issue with OCP or OVP kicking in here? Or does this mod not run into that issue? I'm looking to run about 1.3 to 1.35v.

[RSDXzec]

yeah im also trying to figure out how to do the mod on a rev 1.1 285. could anyone help out in my thread please?

Cheers

[chispy]

Guys the Mod works , just follow the pics at that website , use google translator and you will be fine . Its very very hard to solder that tiny pin # 19 just take your time and be careful , i have killed a card already trying this mod ok , beware of the risks involved .


Chispy.

[RSDXzec]

Guys the Mod works , just follow the pics at that website , use google translator and you will be fine . Its very very hard to solder that tiny pin # 19 just take your time and be careful , i have killed a card already trying this mod ok , beware of the risks involved .


Chispy.

thats why im trying to be really careful with this. Would you be able to answer some of the questions in my thread? and help with the procedure of the vmod? Google translate doesnt clarify much. any help in my thread would be greatly appreciated.

Cheers

[KingK76]

Okay I successfully performed the mod and I am able to increase the voltage to the GPU but I seem to be running into the dreaded OCP issues with the 1.0 PCB revision (solid green or purple screen) at anything over 1.29-1.30v. Now I know the instructions mentioned that OVP or OCP was not an issue but it seems it is for me. Looking at the picture with the wires going everywhere (the shot that initially intimidated me) it seems he does have a OCP mod done with a 100kohm variable resistor. Now I am having trouble seeing the proper solder point there and would like to know at what setting should the vresistor be set at. Any help on this one would be awesome as my version 1.0 PCB 285 is able to hit 828core and 1836shader and I would like to be able to run both of these cards at the same clocks. And so you know the 1.1 card actually runs cooler by about 3 or 4 degrees celsius then the rev 1.0 card at equal volts so it shouldn't be temperature messing things up. Thanks.

[Mayk-Freak]

My GPU Mod MSI 285GTX 2GB sorry for the bad pictures thy were made with the handy.




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[EL RICHARDO]

I have now a Asus 285 TOP with the uP6208AM / VGK939 voltage controller like the one on this page: http://www.syndrome-oc.net/articles....page=4&lang=en I know that pin 9 is the one to use. Anybody has a clue what pot value should I use? Many thank's.

[NapalmV5]

285 1gb/2gb ver1.1 OCP mod

dont thank me.. thanks goes to crotale for the ver1.0 ocp mod

pic by chispy



i used a 1k resistor and gained a boat load of clocks @ stock/air cooling on the 2gb evga ftw

good luck!!


ill post results shortly

[NapalmV5]

ocp mod results

ocp: only mod
vgpu: default
vmem: default
cooling: stock/air

clocks gained from ocp mod
core: 18mhz
shader: 36mhz
memory: 162mhz

the 1250mhz mem is actually 1242mhz



if i got time today ill try vgpu mod

[chispy]

Thanks for sharing napalm

chispy

[Sebastione]

Hi ,
is anybody willing and able to perform the OCP/VGPU mod on the 2GB model against payment? I figured that i simply cant do it ....

[Sebastione]

The OCP Mod:
Does it have to be that tiny resistor or can i use another ground?

[CryptiK]

You can use whatever ground point you want technically.

[NapalmV5]

if you do the ocp mod.. decide to remove it.. and may remove more than need be removed.. your 285 doesnt boot

heres the fix

connect whatever is left of the ocp point to the resistor in the blue encircled area

[Hazzan]

working perfect...thanks all especialy @Crotale

[Brama]

if you do the ocp mod.. decide to remove it.. and may remove more than need be removed.. your 285 doesnt boot

heres the fix

connect whatever is left of the ocp point to the resistor in the blue encircled area

Is the connection 3 on SMD component a ground? If yes, I suppose I could connect a simple resistor of 15 K between point 2 and any ground nearby.

Do you agree?

[Turrican]

a buddy mine a question about this mod

hello, i got some questions concerning the ocp-mod.
which resistor values are measured between the marked points without mod?
I measured about 26.1 kohm at my BFG OC.

after mod, which resistor value is recommended for stock/air cooling?

[@Starsky]

hello, I am Turrican´s quoted buddy.
additional, I did step 1 (pencil mod) successfully, the card does quite fine (max. : 750/1700/1512). but after longer period of gaming at that clocks card is throttling or I get bsod, so ocp-mod maybe could help?

[CL3P20]

...the GTX275 I mod'd recently showed solid gains from adding input caps on the power phases...it appears as if the OCP mod is helping with excess ripple "tolerance" that is common when you have insufficient capacitance in the circuit. Would be nice to see some results on adding 4x input caps to these 285's... if someone would be willing to test. I used 16v 1800uf caps btw..GPU was running small bump in voltage at 1.25v, 756c/1625s on stock cooler.

Thanks @ the OP ..mods are always appreciated

[CryptiK]

I have modded my 285 with 4 x 220uf Tantalum caps but on the phase outputs, and gained 36MHz core at the same voltage.

Napalm experimented with larger electrolytics on the input side with reported gains also.

[@Starsky]

I soldered ocp mod like shown, resistor values were ok but the mod doesn´t work and furthermore the display shows only black.
system starts, card fan is blowing, the card´s status led shows green and the system boots normal into os (I can hear the windows 7 jingle).

any ideas what could have gone wrong?

tia