8800GT voltage mods

[Niccolò]

Simply: No, it just doesn't work right. I just soldered a couple cheapy Radio shack resistor in parallel and it worked great.

I dont' understand, why it shouldn't work?
The goal is to reduce resistance as long as you do it, it doesn't matter the way, does it?

[Renegade5399]

Because you have to be sure the value you lower it is the same on each power phase. Pencil modding it won't get you a reliable and stable result.

[Niccolò]

what happens if their not the same value? I couldn't believe anyway so i tried. Result seems good altough their not the same exact value ofcourse. It doesn't crush anymore under load at 1.45v and 850gpu. Values are 924Ohm and 937Ohm. Should i expect some kind of problem set this way?

[Renegade5399]

No, those are pretty close in value.

[Bellisimo]

Having some problems with the ASUS EN8800GT, i found a vgpu mod
http://forums.overclockersclub.com/?showtopic=157627

but i need to find a vmem/ocp/ovp mod, anyone can help me?
greatly appreciated

datasheet of the voltage regulator
http://www.st.com/stonline/products/...e/ds/12144.pdf

[HitandRun]

Having some problems with the ASUS EN8800GT, i found a vgpu mod
http://forums.overclockersclub.com/?showtopic=157627

but i need to find a vmem/ocp/ovp mod, anyone can help me?
greatly appreciated

datasheet of the voltage regulator
http://www.st.com/stonline/products/...e/ds/12144.pdf

Linked datasheet is for the vgpu voltage controller! Post # 832 same as the Galaxy 8800GT. Working on the OCP/OVP. What mem voltage controller do you have on your card?

[Bellisimo]

Linked datasheet is for the vgpu voltage controller! Post # 832 same as the Galaxy 8800GT. Working on the OCP/OVP. What mem voltage controller do you have on your card?

i already knew it was pin22, but thx anyway, trying to figure out the ocp/ovp also, but not sure on how to do this
did you find the solution for your freezing problem?

will look for the memory regulator

[Bellisimo]

hmm, think i have found the ocp resistor and the ovp resistor
possible the ocp resistor is 8kohm and the ovp resistor is 130k ohm?

fount the mem controller i think: APW7065

http://www.anpec.htm.tw/ashx_prod_fi...me=APW7065.pdf

[HitandRun]

HitandRun,
OCP: find a surface mount resistor connected to pin#35, measure resistance across the resistor (basically between pin#35 and ground). Solder a VR rated ~20 times the measured value across the resistor. Lower resistance to push back OCP trigger point.

About OVP (as per PM)....
Does the card crash if you increase voltage without any load on the GPU?

Sorry for the late response, very busy at work! Largon Pin # 35 to ground is 6.47kOhm. Regards to OVP. Card shuts off in idle when more than 1.5V is applied.

hmm, think i have found the ocp resistor and the ovp resistor
possible the ocp resistor is 8kohm and the ovp resistor is 130k ohm?

fount the mem controller i think: APW7065

http://www.anpec.htm.tw/ashx_prod_fi...me=APW7065.pdf

Nice! What memory do you have on this card?

[Bellisimo]

Sorry for the late response, very busy at work! Largon Pin # 35 to ground is 6.47kOhm. Regards to OVP. Card shuts off in idle when more than 1.5V is applied.



Nice! What memory do you have on this card?

some qimonda crap, can overclock to ~1060 MHz
good to know 6.47 kOhm is required for 1.5V :d

[CL3P20]

Just thought I would share a pair of GS's I mod'd for a member over on OCN's GPU farm...cheers!

EVGA 8800GS's, GPUv @ 1.24v idle :stock cooling
808mhz core
1944mhz shader strap

GPUv and Vmeasure by :CL3P20

[renzokuken]

HitandRun,

Regarding the first picture (of the "chip") in post #832, where is this chip located? I have a Galaxy 8800GT 512mb and I cannot find this chip. Is it on the same side as the ram chips / GPU core or on the other side of the card?

[renzokuken]

nm, found your post on blazingpc and I found out it is on the same side as the gpu/mem.

Another question though, I have the Accelero S1, Rev 2 on my card. My card idles at 1.25v and immediately jumps to 1.35v with FurMark. After about 60 seconds, it slowly climbs to 1.39v at which point FurMark crashes, my DMM reports 1.25v again and then Vista tells me that the driver was restarted (sure beats XP's permanent lockup). Anyway, at the point of crashing, rivatuner reports temps at roughly 65 degrees. What I would like to know is this: what is the cause of this? Is this OCP kicking in? OVP?

[natedog420]

DO NOT USE FURMARK ON THE 8800GT'S. i cant say this enough unless you want a dead card. you can look throught this thread and find others on the net that have killed there 8800gt's with furmark because it puts a lot of stress on your card and it will for some reason kill it.

this is the mod i did by removing the 2 in the pic and i ran 1.5 on water for awhile with almost 900 core being stable for 24/7 and crysis. but this is the dirty way and there are different ways to do it just didnt find the pic and got tired of looking. btw when adjusting voltage before on mine i wasnt paying attention and i seen 2.0 volts on the dmm and it shutdown but all was fine after a restart thank god. pretty tuff little cards but the memory sucks.

edit: i also have the asus 8800gt good card so far. been pushing it for awhile now going on a year and when the volts are high you can hear it screaming for less volts lol

[renzokuken]

OK, I won't use Furmark anymore. However, the same thing happens when playing Crysis. It's fine for about 5-10 minutes and then the graphics become corrupted and it locks up. Temps don't go above 60 degrees. The only way out is to continuously spam Alt-Tab until it registers the button press and switches back to the desktop.

I have exactly the same card as you btw HitandRun. My voltage jumper pins are next to the dual pci-e power connectors just like yours instead of on the long edge of the card like the other Galaxy 8800GT model.

[krudki]

Hi guys, I gotta question. I have read on XS, that OC more than 1000 on memory is danger. I got galaxy 8800GT HDMI version with 720 / 1800 / 1100 on stock cooling, so I should decrease mem to 1000 ?

[renzokuken]

krudki,

What you have read here on XS is correct. You can find more information regarding the issue, including a description of exactly what the problem is, here.

Whether or not the problem applies to a non-reference 8800GT (such as the Galaxy model) is a different question entirely and one that I myself am still trying to find the answer to however I suspect it does.

[germtangc]

Hit and Run,

I applied your galaxy 8800gt volt mod to my galaxy 9800gt (they have the exact same PCBs and components). But right now I'm having trouble with OCP it seems. My stable to date is 750/1900/1000. I've read your posts above regarding pin #35 as the "OCP" pin. I'd like to know if you got around making the OCP mod work?

My card's OCP is somewhere 1.38v i think.

[renzokuken]

My card's OCP is somewhere 1.38v i think.

I think mine may be about the same, and I am equally interested in an OCP mod for the Galaxy 8800GT

[Vatos_locos]

just remove the resistor on the ovp pin and it will work at least that happened to mine

[germtangc]

Hit and Run,
can you show us the resistor connected to pin #35 for the OCP mod (GALAXY 8800GT) ? My eye is not good enough to trace the line from pin #35 to the resistor i'm looking for.

[HitandRun]

Hit and Run,

I applied your galaxy 8800gt volt mod to my galaxy 9800gt (they have the exact same PCBs and components). But right now I'm having trouble with OCP it seems. My stable to date is 750/1900/1000. I've read your posts above regarding pin #35 as the "OCP" pin. I'd like to know if you got around making the OCP mod work?

My card's OCP is somewhere 1.38v i think.

Yes sir! The mod was done and confirmed working! I'll take some pics and post it!

[germtangc]

hit and run,
thank you. i'll wait for it.

[pest]

i vmodded my ecs 8800gt according to this thread

that's the result i've come up so far

it's a bit of a crappy card, needs 1.38V Load, but anyway, i'm really happy with it
cooled by an AcceleroS1, Temperatures never go above 60°C

note that the Bench is with Vista64, with WinXP 16k should be possible (no LOD was used)



cudos to everyone who is contributing to such threads

[HitandRun]

hit and run,
thank you. i'll wait for it.

Sorry since it took me a little while but here it is. OCP mod done tested good for 1.6V on air. I used a 100K VR and turned it down to 40K which resulted in no more voltage cut-off at 1.5V when before the mod.