8800GT voltage mods

[tralalal]

on air
vgpu 1.45v
vmem 2.05v

[hashwood]

First of all I have to say thanks. I read almost all this thread, and with all your help I was able to do the GPU mod.
I didn't use the soldering iron, because I don't want to loose the warranty, I made the mod using Bison Electro . It was easy, so easy that after I made it first time, I clean it down in one hour, because I suspected the card was damaged. I couldn’t get 3dmark to run even at stock. It was because of CPU oc, I loaded some unstable bios setting, while I wanted to test the card
Last week I installed Maze 5 wb, and the temps max at 45 with 1.3 under load. In the process I wanted to make sure the ram heatsinks will not fall off, and I added some AS thermal adhesive on the memory (uncutted).
Now my problem is that before the WB, using zalman cu900, and the same heatsinks (sticked just with thermal paste), I was able to run the card mem at 1950mhz. Now it's not stable at stock (1900), it only works at 1850 (with stock everything). The GPU hits 850 easy, but with the mem at 1850 I'm doomed. I don't plan to stress the Hynix memory too much but I expect 1950.
I must add that I tried everything to cool down the heatsinks, and the only conclusion is that the AS adhesive, is somehow not doing its job on one heatsink or maybe multiple ones. Or am I just missing something else?
Unfortunately the only solution is to take them down and stick them again with cutted AS adhesive, but as I read this is very hard (freezer) and risky.
Maybe I’m wrong, but I don't think there is another explanation. I just posted to tell my story, and maybe some advices.

[EvoCarlos]

hey largon
the reading from pin 4 to gnd is 615ohms with volt mod active forgot to get a reading with it off
also if ive read my multymeter right
sorry for the delay real life was calling

[h3x0r_1984]

I have a sparkle 8800GT , cooled by a GX810 Zerotherm . I vmoded it , and set VGPU at 1.3V . The memory is quimonda...si it doesn't clock very high...but i got 800 core / 1950 shaders stable in Crysis with AA4X at 1280 .

I'm worried about the temp . In Crysis or other games,the temp hits about 66 degrees , but in FUR , i get about 80 Degrees . I've changed the thermal compound with AS5,so i'm expecting it'll drop a few degrees,but it still seems a bit high .

Am i safe with this voltage 1.3V , 24/ 7 , without damaging the card ?

[EvoCarlos]

i got scared with my ecs8800gt as i got all but no improment from 1.09 -1.3v so have put it back to stock as my temps were just rizing i get more points on 3dmark06 with 730mhz core @ 1.09v than i do with 800mhz @ 1.3v somthings a miss and i need some one to explain why as im noob at vmod this is my 1st one

just did a run on 3dmk06 and got this = 20541 volt mod off lol
http://service.futuremark.com/compare?3dm06=7046102

[DINGO]

would any one have a dead card with an RT9619A chip on it they would like to part with? if so please PM me and we could work something out

[Luka_Aveiro]

I have a sparkle 8800GT , cooled by a GX810 Zerotherm . I vmoded it , and set VGPU at 1.3V . The memory is quimonda...si it doesn't clock very high...but i got 800 core / 1950 shaders stable in Crysis with AA4X at 1280 .

I'm worried about the temp . In Crysis or other games,the temp hits about 66 degrees , but in FUR , i get about 80 Degrees . I've changed the thermal compound with AS5,so i'm expecting it'll drop a few degrees,but it still seems a bit high .

Am i safe with this voltage 1.3V , 24/ 7 , without damaging the card ?

DO NOT USE FUR TO TEST YOUR CARD! IT WILL KILL IT!

(snip)

From my experience, the more Core/shaders frequency, the lower mem freq you have to use, at least with qimonda chips, hynix shouldn't be much different, i suppose.

[Merc1212]

From my experience, the more Core/shaders frequency, the lower mem freq you have to use, at least with qimonda chips, hynix shouldn't be much different, i suppose.

This has also been my experience - mem used to do 1950, but now (post gpu volt mod) it will only do 1850mhz with the core at 825mhz. Not sure whats up... gpu volt mod stealing some juice from the mem perhaps?

[walshlg]

EvoCarlos -> you may want to do the 3dMark test again

[loonym]

They had pny 8800gt on sale this weekend at bestbuy for $149 so I got a couple. I never did any mods before so don't laugh too hard I used single turn trimmer.

[EvoCarlos]

EvoCarlos -> you may want to do the 3dMark test again

like this one --> lol http://service.futuremark.com/compare?3dm06=7053938
volt mod on @1.3v

i just dont get it so why am i volt modding again it just dont add up

no vmod 20541 marks 730/1820/1017
vmod 21058 marks 800/2000/1000

517 marks thats hardlly worth writing home about...

[Luka_Aveiro]

This has also been my experience - mem used to do 1950, but now (post gpu volt mod) it will only do 1850mhz with the core at 825mhz. Not sure whats up... gpu volt mod stealing some juice from the mem perhaps?

I believe it has something to do with the IMC (integrated memory controller), maybe loosening ram timings would be a good idea for higher mhz, don't know however if it would benefit you overall performance.

[Benji Tshi]

Hi,

There is a lot of different ovp mod, i'm not sure that every one works perfcectly.
Did anyone find it and can set 1.6v on gpu ?
I need it, LN2 is coming last week so i don't want to be stuck at 1.4v. Please help me!

Thanks

[quake6]

I have similar problem... If my clocks pass 890/2052 (gpu/shader) and voltage is >1.5v,it freeze it.I did OCP (2x1.2k ohm resistor) and dont know what else to do... Any advice? Temperature wont pass 50°C

[EvoCarlos]

so i just want to confirm that the vmem power regulater on the stock 8800gt is the same as the non refrence card i have.
i.ve been looking at the data sheets for the stock and my card and want to do the vmem buck mod



so will a 50k to pins #4 and #13 work the same on my card?? mine is the APW7067N chip

[largon]

quake6,
It's very likely your GPU is maxed out. 900MHz seems to be somekind of cut-off freq for G92.

EvoCarlos,
Yup. APW7067N and ISL6549 are pin compatible.

[jason4207]

I need some help. I looked through this thread, but the XFX pictured earlier in the thread doesn't match the pic I have.

Can anyone help me find the correct mod points and read points on this card?



vmem= 6549C8Z
P7408TL


vgpu= ISL6568
CRZ
M744FD8

Thanks!

[yiancar]

edit : find the fb pin from here (6th one) http://www.intersil.com/data/fn/FN9187.pdf

and see where it is connected to , and measure the resistance from there to ground

[Vatos_locos]

do that yiancar said if this resistor has 0 ohms with the Fb leg pin 6 on the link http://www.intersil.com/data/fn/FN9187.pdf then mesure the other side of the resistor if it is grounded then tis is your spot how many ohms are from the Fb to the ground ?

[Janchu88]

hi, is there any mod for my card?

I have a Gigabyte 8800GT 256MB... here some pics





soldering or conductive ink or anything else?

edit: could provide the pics at double size if needed...

[yiancar]

tell us the name of the following chips plz

[oohms]

http://www.xtremesystems.org/forums/...te#post2872009

[jason4207]

edit : find the fb pin from here (6th one) http://www.intersil.com/data/fn/FN9187.pdf

and see where it is connected to , and measure the resistance from there to ground

do that yiancar said if this resistor has 0 ohms with the Fb leg pin 6 on the link http://www.intersil.com/data/fn/FN9187.pdf then mesure the other side of the resistor if it is grounded then tis is your spot how many ohms are from the Fb to the ground ?

I'll get back to you. I don't have the card yet. A buddy of mine wants me to mod it for him. I'll see if he can take some measurements.

(Fb to GND) x 20 = ~VR

[scottc19]

Just a small update... I have been successfully running that xfx 8800gt that I bought back from the dead, from another board member who broke it volt modding. I have also been running it 24/7 with 1.5vcore idle. With a water block, heatsinks, and a fan. So it seems that 1.5 is stable and at least somewhat safe. I dont know how long its been, but at least 3 months. I posted a while back and thought that this 1.5 had damaged it, now I have comfirmed that it is still fine. I'm not suggesting that everyone crank theres up to 1.5, but just take it as food for thought.

[Janchu88]

http://www.xtremesystems.org/forums/...te#post2872009

hi, it says "lower resistance to ground" on the green marked resistor for increasing Vgpu... could it be penciled, too?