8800GT voltage mods

[Wile E]

Removing the SMR wouldn't work.
In order to push back the OCP trigger point you're going to have to solder a 20kΩ resistor (yup, not 20× the measured R, 4× is plenty for this purpose) between ground and any a pad directly connected to pin#17. The resistor doesn't have to be a VR. This would puch OCP trigger by 25%.

Ok, thanks Largon. I think I'll use a VR, in case I need to tune further. One last question, is it more, or less resistance to to push the trigger higher?

[largon]

Lower Ω -> OCP weakens.

[DINGO]

biggest thank you @ Wile E and largon, you managed to answer my earlier question on OCP, Cheers

[Pacha]

I finally put my GT into my rig after having let it a few months lying on the desk.
It has Samsung chips and vgpu mod is done.







I'll be testing it soon.

What temps or correct between GPU-Z and nvidia control panel ones?

[largon]

^Talk about ramsinks!

I think GPU-Z give a bit too low temps, like 8ºC too low. And GPU-Z can't be right when I look at my ambients.
Dunno if there's discrepancy between Rivatuner (which I use) and nvidia control panel...

[Pacha]

ram sinks come from a NB sink of a dead asus mobo that I cutted and stuck with AS adhesive. they are cold at the moment, card idling. I have to see how it performs in 3D.

nvidia cp and riva report the same temp, so it is 29°C idle, I guessed that gpu-z was wrong. But the second probe has the same value in riva, nv cp, and gpu-z. what is weird is that the wb is cold and doesn't give me the impression that the core is at 29°C, it was a bit hotter with my X800 for the same temp.

Is my temp normal? I've tested mounting with a "blob" of mx-2 instead of spreading. I have idle temps a bit higher than my X800 which was running at 1.7V (instead of 1.35V stock).

[largon]

29ºC is perfectly fine, what I really want to know is your load temps and don't forget to mention freqs & volts. And what is the maker of the waterblock? I'm looking at 38ºC idle (1.238v) and 41ºC load (1.324v) with 846/2268/1044 (DDR-2088). Cooled with Swiftech MCW60 retrofitted with a baseplate from Apogee GT(X) CPU block, GPU is in the same loop with Q6600 and P35 MCH.

One can tell GPU-Z isn't giving the correct figures simply because 21.5&#186;C would mean ambient air temps <<20&#186;C...

[HitandRun]

^Talk about ramsinks!

I think GPU-Z give a bit too low temps, like 8ºC too low. And GPU-Z can't be right when I look at my ambients.
Dunno if there's discrepancy between Rivatuner (which I use) and nvidia control panel...

Yeah! Look like the ones I made for my card! Nice job!

[Pacha]

Yeah! Look like the ones I made for my card! Nice job!

thanks

[Pacha]

29&#186;C is perfectly fine, what I really want to know is your load temps and don't forget to mention freqs & volts. And what is the maker of the waterblock? I'm looking at 38&#186;C idle (1.238v) and 41&#186;C load (1.324v) with 846/2268/1044 (DDR-2088). Cooled with Swiftech MCW60 retrofitted with a baseplate from Apogee GT(X) CPU block, GPU is in the same loop with Q6600 and P35 MCH.

One can tell GPU-Z isn't giving the correct figures simply because 21.5&#186;C would mean ambient air temps <<20&#186;C...

wb is a CPU wb, manufacturer is 1A-Cooling and model is SL2.
the mount is homemade as there is nothing on sale to hold my wb on the card. I have the same wb for CPU, both in parallel.
this idle temp was with stock vgpu.

What would be the reason of so much difference between GPU-Z and riva tuner? GPU-Z is updated so often that it is weird they're holding onto this misreporting.

EDIT : I'll tell you more about load temps at different voltages tonight, I'm not at home at the moment

38 idle and especially 41 load is very good with these voltages I must say, I don't know if I'll be able to maintain such a low delta

[RLM]

Can anyone confirm where the VGPU read point is for the XFX 8800 GT XXX. I've tried taking readings off the mosfets, but don't get close to a 1.1v or 1.05v reading.



RLM

[largon]

[GFDuke]

I finally have everything set up again. I have to say i am impressed with this vgpu mod. Now getting over 800 core. Unfortunately my rma'd 780i mobo came with the po4 bios and it's limiting my fsb. Or at least that what i think it is. I cant seem to get 4.5ghz like i did with my old board. And, when i do managae to boot to windows at 4.5 i lock up in 3d06. I'll have to spend some more time with it and see if i can figure it out. I've done the vdroop mod. I dont know what else i can do. Try some diff multi's i guess. But the gpu's are rocking on these cards now and they're just itchin to break my old records.
1.23vgpu idle, 1.27vgpu under 3D06 load
http://jbpainting.net/vgpumod3d0622078.jpg

[RLM]

Well I had a stab around in the dark myself and found a possible other location for VGPU reading. Thanks Largon for taking the time to do that. Much appreciated



Interesting, in bios I increased voltage tables 1-4 by .1v each and set 3d to 1.2v. After the bios mod I had a reading of 1.15v from that point. Is that pretty standard?

Now with a hard mod I'm reading 1.2v, from both my VGPU point and Largon's recommended.

EDIT: Can confirm possible VGPU read point is actually spot on and scales with the other read points. Volt mods works a treat thanks

Cheers

RLM

[Pacha]

largon I was impressed seeing your card at +3&#176;C loaded but I am currently running at 31&#176;C idle, and 32&#176;C in game (stock freq & vgpu), weird that it doesn't get much hotter than that, tests that have been made with air show so high load temps with such difference between load and idle.
I'm maybe leaving for a few days tomorrow, will be benching it with higher vgpu and freq after that.

[bigghost]

hi,there i made the vgpu mod yesterday on my gts.
but i must say that i got no more overclock with it. why ? maybe i got a really bad gpu ?
some infos now.
i use a zalman watercoolblock.
default load vgpu is 1.22v i can overclock to 820mhz 3dmark06+gamestable.
i had used 1.35 load and 1.45 load but 850mhz never stable.i got blackscreen after some secs
ati-tool or 3dmark.after some secs the screen come back and all looks normal.no reboots or something else.
never had more temps as 60degrees.shaders i get 2050 with default vgpu.2100 is not stable too.
maybe any one a idea for get better results ?
thx

[scottc19]

Most likely you are hitting the ovp (over voltage protection) limit and the card is shutting down. Try 1.3v and see what you get (I dont think this will trip it, but I dont remember what the exact limit is). Otherwise you have to do the ovp mod...
Hope this helps

[HitandRun]

hi,there i made the vgpu mod yesterday on my gts.
but i must say that i got no more overclock with it. why ? maybe i got a really bad gpu ?
some infos now.
i use a zalman watercoolblock.
default load vgpu is 1.22v i can overclock to 820mhz 3dmark06+gamestable.
i had used 1.35 load and 1.45 load but 850mhz never stable.i got blackscreen after some secs
ati-tool or 3dmark.after some secs the screen come back and all looks normal.no reboots or something else.
never had more temps as 60degrees.shaders i get 2050 with default vgpu.2100 is not stable too.
maybe any one a idea for get better results ?
thx

What is the voltage on the GPU at the moment of the black screen! If it goes to zero than the OVP is activated and you need to mod this as well!

[EvoCarlos]

did my 1st ever volt mod on my ecs8800gt none reffrance cards looks cool but cant get anywhere near stable water cooled its hitting 60c and lots of crashes and black flahings
add'd some of the smallest switches i could find so i can go back to 1.07v
went to 1.23 no load and 1.25 3d load
craps out on shader i think
any who some pics





sli volt mod

[DINGO]

long story short i have blown the mosfet driver chip (RT9619A) through sheer stupidity and clumsyness,
would anyone have one of these chips on a dead card they would be willing to part with?
please PM me if you could help. many thanks

[tralalal]

Hello evrybody. Is there anybody who could help me?
I made vmod in my graphic card. When i increase the voltage abowe 1.13v in
Auamark3 , the voltage reaches the value 0 in the measured points

Please help me. I enclose the photos without vmod

[_Unstoppable_]

Hello everyone,

I'm about to voltmod my XFX 8800GT Alpha Dog. So in this thread I found the following picture with the solderpoints for doing this:



But I can barely read what it says on the vGPU (red), also the vMEM (green) but I wasn't gonna mod that one

So where do I need to solder exactly?
Also, what kind of resistor should I use? How much Ohm?

Thanks in advance!

[largon]

tralalal,
Your problems are caused by OVP (over voltage protection). You can push the OVP tripping-point further by soldering a resistor between the points marked with red dots in this pic:



Oh, and...




_Unstoppable_,
You should PM RLM and ask since he's the one who posted the pic and has soldered the mod.

[tralalal]

I did what you told me to do, but the problem still exists

[largon]

As I re-read your original reply I realized you said:

When i increase the voltage abowe 1.13v in Auamark3 , the voltage reaches the value 0 in the measured points

Does this "in Aquamark3" mean it only crashes while load? So it doesn't crash to 0v when you tune the vGPU without any 3D load, like when you're on the desktop?