6600gt AGP voltmod

[nd4spdbh2]

Alrighty.... i am FINALLY getting around to peoples wishes of putting up a 6600gt AGP voltmod, seems as how the VrZone one is imageless... SO here it is. The pictures that i have attached to this thread are in case the ones showing are down due to me moving a webhost... they are in the same order.. ALSO i take ABSOLUTLY NO RESPONSIBILITY if someone skrews up their card... NOT MY fault.. ALSO DO NOT DO THIS if you dont have aftermarket cooling like me :beer:

~6600gt AGP 128MB Volt Mod~

The test subject, a LeadTek 6600gt AGP 128MB with a MASSIVE hs and nice quiet fan (background)...

NOTE: Take note where the purple capacitator and teal blue one are located on the middle bottom right of the picture i will refer back to thoes shortly.

http://teamlosi.andrevas.net/pics/comp/gfx%20card/voltmodthread/testsubject.jpg

OK before you go tearing into your computer soldering or pencil shading You NEED to see what your cards Vcore is running at STOCK... so heres a pic of where you to test.... the red circle represents a Positive vcore test pin.... just place the positive tip of ur multimeter on this and the negative on a ground, like the actual case or the ground external power to the card. NOW the thing is this number you read will differ between idiling on the desktop in 2D.... and in 3D mode.... it will range by .1 volt.... stock being right around 1.35 in 2D and 3D being 1.45 (thats what my card reads the VIDS say it should be 1.3 and 1.4 but i trust my multimeter more) SO go ahead and get a reading of it sitting there on the desktop... mine reads 1.333 on the desktop.

http://teamlosi.andrevas.net/pics/comp/gfx%20card/voltmodthread/vcore.jpg

NOW to get some numbers... I SWEAR we will get to the actual mod soon... DONT skip this... it will give you some good satisfaction.... OK what i did to make sure this mod worked was to use Nvidias DETECT OPTIMAL FREQUENCIES option.... SO if you dont have it go search for coolbits 2.0 and iinstall that and go detect optimal frequencies.... when i do so on stock voltage it spits out a core MHZ of 577 and ram of 1050.... OK with thoes numbers in mind lets DO IT!!!

ALRIGHTY the resistor we will be looking at is circled in the below pic and is INBETWEEN the purple and teal blue capacitator i stated above (SEE THERE IS A METHOD BEHING MY MADNESS). This resistor stock should measure right around 420ohmz.... mine says 417. Now according to VRZONE shading this resistor with a pencil down to 370ohms will result in a .1 vcore increase... but in my expierence right around 385ohms will result in a .1 vcore increase... SO go ahead and shade to what you want... i wouldnt recommend n e thing below 360-370 with good GOOD cooling so for me i just went down to 385ohms for a .1v increase.

http://teamlosi.andrevas.net/pics/comp/gfx%20card/voltmodthread/resistor.jpg

QUADRUPLE CHECK your resistance before putting it into your computer. then hook everything up and get ready to test the vcore voltage when you press the power button as this will reflect a 2D voltage in my case 1.44 volts ( a .11 volt increase over stock 1.33 in my case)

Now we know we are feeding the core more voltage but did it really work? Go back to the DETECT OPTIMAL FREQUENCIES and press that button.... in my case with a .11v increase i got a Core MHZ of 608 and Ram of 1120... IT DID SOMETHING.... now if you have gotten this far im sure you have the knowledge of getting the most of your overclock out of the card seems as how the frequencies that nvidia finds are about 3/4ths of the oc that is achievable... N E WAYS happy modding and good luck... and please NO FRIED CARDS the 6600gt is pretty damn good... would want to go ruin a good thing.

[four4875]

nice, i need to mod mine sometime, but i need to get a better cooler on there. been experamenting with it lately see what i can do better than stock.

[Centercore]

:cry: So happy you got this and I cant wait to try it.

The only 6600gt volt mod how to on the net :D

[nd4spdbh2]

:cry: So happy you got this and I cant wait to try it.

The only 6600gt volt mod how to on the net :D



HE HE OOOOO YEAH you kno it... now dont go burn up ur card.... that wouldnt be cool.... he he takin my card out today gave me the chance to take the HS off, let the card straighten out... YES it has a lil bend to it from the weight of the hs.... clean the hs of dust and put new as5... temps are a couple *c lower too! I am TEMPED to do a Ram voltage mod but i really dont want to skrew up my ram.... i would like to be able to get active cooling on it but the 6600gt AGP has its ram sooooo close to the core its hard to get a big cooler on there with ram sinks.

[Centercore]

I found the ram has a bigger performance impact than the core oc.

[Hipcrostino]

i have a volt mod for the ram on 6600gt agps. It works quite well, but i also killed my card doing this mod (dodgy VR :( ) so just watch it. It is also a resistor shading job (or a vr if you crazy like i was). Im at work right now, will take some pics of my 6600gt (which is dead) and post them up here as well.

Good work nd4, this is the kind of thread i was looking for, took me ages to find the mods. I never even got the try the core mod. But then, my core did 605Mhz on stock volts :P

[FlailBoy]

Interesting. I'm using a vf700cu. I don't figure I have too much to lose w/ this mod; and temps did improve quite a bit (<50 load).

Would you go for it with that cooler?

[nd4spdbh2]

Interesting. I'm using a vf700cu. I don't figure I have too much to lose w/ this mod; and temps did improve quite a bit (<50 load).

Would you go for it with that cooler?


OH ya a vf700 is right up there with my p4 hs... go for it but just go slow and dont short n e thing out with your multimeeter probes :beer:

Hipcrostino if you could link to the vram mod that would be cool with also pics of where to measure the voltage of the ram etc... thanks.... and how did you skrew urs up n e way... what kinda VR?

[Centercore]

Alrighty, I did it but only got 590 detect optimal settings. tried 600 mhz on the core and got a few artifacts so it should be good at 590 mhz.I will prebill try again later when I can be bothered.

Also using a normal pencil seems like it makes the resisters omhz go up and down I suggest using a mechanical pencil it works better.

Ohh yeah bring on the vmem mod my stock volt mem oc isnt as good as some other so I want it.

[nd4spdbh2]

Alrighty, I did it but only got 590 detect optimal settings. tried 600 mhz on the core and got a few artifacts so it should be good at 590 mhz.I will prebill try again later when I can be bothered.

Also using a normal pencil seems like it makes the resisters omhz go up and down I suggest using a mechanical pencil it works better.

Ohh yeah bring on the vmem mod my stock volt mem oc isnt as good as some other so I want it.

what did you shade the resistor too and whats ur vcore? YA SERIOUSLY I WANT RAM V MOD NOW!!! an extra 100mhz on my ram would be great.

[four4875]

am i special, or is it normal to be hittin 590 core stock? ive got slightly upgraded cooling, and been hittin 590 detected optimal, and as long as i keep it under 70 C its artifact free.

[Centercore]

what did you shade the resistor too and whats ur vcore? YA SERIOUSLY I WANT RAM V MOD NOW!!! an extra 100mhz on my ram would be great.

I shaded the resistor down to 365-375 to get a 592 detect optimal settings. The result may be due to the zalman heatsink not being tight enough or just needing some reinstalling and new AS5. I noticed that when im at default clocks I get around 50-53 degrees which is not normal because im sure it used to stay in the 40s.

Im also gonna do a p4 heatsink mod when I find some drill bits then I should be good.

[Damenshon]

i tried the voltmod, brought resistance to 380. unfortunately i dont have any working multimeters....so now i can bring the vcore to 570 (550 originally). im pretty sure its the cooling which is drawing me back, im on stock and it seems according to the nvidia temperature program that it hits around 100c atleast above 80C. toasty...

[fireandice]

hmmm isent that a little low? maybe this is why my my 500mhz oc locks up.

i got a 6600 and i shaded the r87 takeing it from 500ohm stock to 460ohm like the vr zone guide said. i could go to 500mhz but when in 3dmark it would lock up.

stock 500ohm highest oc i could get was 453mhz core but it would crash some times but not allways

pencile modded to 460ohm i could run stable at 453mhz highest i tryed was 500mhz what locked up in 3dmark.

that was useing the 6200 guide. now since the 6600 and 6600gt use the same core. sould i lower that resistor down even more? like in the 6600gt guide to 370ohms?




6600 stock 500homs @300-350mhz core.
6600gt stock 420ohms @ 500-550mhz core.


so beaing they bolth use the same cores "NV43AGP" should i be able to drop that resistor down from 500ohm to 420ohm or the 370ohm like the gt's are getting.

[four4875]

i would make sure your cooling is adequate, and check the voltages with a multimeter and keep pushin till you get too hot, or your clocks stop improvin.

[Centercore]

I broke my 6600gt 3 chips of some sort (I dunno where they went so I dunno).

RIP Asus 6600gt

[fireandice]

my cooling is upto it.

[Hipcrostino]

Interesting. I'm using a vf700cu. I don't figure I have too much to lose w/ this mod; and temps did improve quite a bit (<50 load).

Would you go for it with that cooler?

same one, vf700cu

OH ya a vf700 is right up there with my p4 hs... go for it but just go slow and dont short n e thing out with your multimeeter probes :beer:

Hipcrostino if you could link to the vram mod that would be cool with also pics of where to measure the voltage of the ram etc... thanks.... and how did you skrew urs up n e way... what kinda VR?

It was a POS vr i bought. Very stupid of me! But i did to a test penciling the resistor at first. It worked well. I'll try my best to find the vram mod. Its in a huge forum post some place. I'll post some pics in a sec, but be warned they arenn't very good.

I broke my 6600gt 3 chips of some sort (I dunno where they went so I dunno).

RIP Asus 6600gt
sorry to hear it man, i feel you pain.



then i went and bought a 7800gs :D

EDIT: Compressed into one post :D

[Hipcrostino]

Ok here is the Vmem Mod all.

Disclaimer: Niether i or these forums is to blame for damages of any kind caused by performing this mod!! Do at you own risk!

Ok with that out of the way, i will just say that you should try to find out about this mod else where before doing it to get as much info as possible!

Ok there is an attached pic of the back of a 6600gt (mine) with a referance PCB layout. There is a mosfet on the back near the rear top side of the card. There is also a spot for on that is missing. Ok next to that is the chip that controlls the ram voltage. BELOW that are three tiny tiny resistors. There are top-to-bottom of the card orientation. There is also a space for a fourth one, but its empty. The one closest to this missing resistor is the one to adjust the voltage with. Pencil this resistor to increase the volts.

Im sorry i don't have any values for this resistor, but i calculated it useing the value i measeured. Unfortunatly i also can't remember that formula. (it was a while ago!)

the read point is a capacitor on the front side of the board. Its base prongs stick right though the pcb for easy access. Meassure on the positive side of this cap.

Two further warnings!!! :
1. When measureing the voltage i managed to arc my DMM probe to the resistor above it! This was a heart raising moment as the screen went NUTS! Fortunatly i killed the power and it rebooted fine. WATCHOUT for such possibilities, you may not be so lucky!

2. I KILLED MY CARD DOING THIS MOD! Like i said before, i confirm it worked by penciling first, so this mod will work, but i put 3.3 volts into the ram due to a VR hicup resulting in damage. TOO much voltage will damage the ram perminatly!

If your not sure about the mod, DON'T DO IT!

Otherwise go for it, and ask questions if you need to, just remember i did this a while ago so give me a break!

GL guys

[four4875]

anyone know how well these mods would agree with a 10k pot? its all the local radioshack has in 20 turn. i think ima take my card to work tomorrow and play with it in my a7n8x, never had it in a good board, just my pos pcchips p4. might also solder on some pots if they wont kill it. although im not sure if ill be able to mount a hs i have on it or not, an old s423 or whatever it is p4 hsf, if all goes well ill be drillin and tappin it, but the 6600 has to be cool and have ridiculously spaced holes compared to every other vid card. makes things difficult for mountin a real hs. damned cast alu. stock pos...

[four4875]

got a stock socket a cooler on there, drilled and tapped to m3x0.5 screws, put on some paper washers and screwed it on. need springs, but this seems good so far. no vmod, up to 625 core stable, gets to ~60 C, bounces up to 61 occasionally, in rthdribl.

[four4875]

without doin the vmod, my test point is readin 1.616v, ran 2.03v. testin idle shows 1.48v, is it safe to push it? right now im artifactin at around 60 C at 630 core in rthdribl. at 590 mhz i was artifacting at around 75 core.. think more V would do the trick? how high can these cores take, at what temps? before upgrading the cooling it would hit in the 80s regularly just gaming, at stock speeds. but the thermal interface was nonexistant from people messing with the card. i got it for $15, it was dead, i replaced a cap (actually, the one at the ram test point) and it came back to life. so its not that huge of a financial risk to me, aside from the fact i would be without a video card.

[Hipcrostino]

they can get pritty hot, like 80-90 and run ok, but personally i didn't like going over 70. I had mine running <60 underload with the zalman cooler and i could run 605mhz on the core with no artifacting at all. Looks like you have a good core there. The jump in volts between idle and load is normal, they change clock speed in 2d mode to save power so thats normal. unfortunatly i can't remeber te voltages i had so i can't help you there, but they sound right atm. a .1v increase on the core will yeild a good gain most liklly so you gotta take it slow!

gl

[four4875]

running 1.708 core 3d, according to fluke. got to 630 stable in 3dm01, 03, and aquamark 3, all i have on the work comp, havnt gotten it back in my home comp. i think it likes the a7n8x more then the crappy pcchips p4 board.

[nd4spdbh2]

Ok here is the Vmem Mod all.

Disclaimer: Niether i or these forums is to blame for damages of any kind caused by performing this mod!! Do at you own risk!

Ok with that out of the way, i will just say that you should try to find out about this mod else where before doing it to get as much info as possible!

Ok there is an attached pic of the back of a 6600gt (mine) with a referance PCB layout. There is a mosfet on the back near the rear top side of the card. There is also a spot for on that is missing. Ok next to that is the chip that controlls the ram voltage. BELOW that are three tiny tiny resistors. There are top-to-bottom of the card orientation. There is also a space for a fourth one, but its empty. The one closest to this missing resistor is the one to adjust the voltage with. Pencil this resistor to increase the volts.

Im sorry i don't have any values for this resistor, but i calculated it useing the value i measeured. Unfortunatly i also can't remember that formula. (it was a while ago!)

the read point is a capacitor on the front side of the board. Its base prongs stick right though the pcb for easy access. Meassure on the positive side of this cap.

Two further warnings!!! :
1. When measureing the voltage i managed to arc my DMM probe to the resistor above it! This was a heart raising moment as the screen went NUTS! Fortunatly i killed the power and it rebooted fine. WATCHOUT for such possibilities, you may not be so lucky!

2. I KILLED MY CARD DOING THIS MOD! Like i said before, i confirm it worked by penciling first, so this mod will work, but i put 3.3 volts into the ram due to a VR hicup resulting in damage. TOO much voltage will damage the ram perminatly!

If your not sure about the mod, DON'T DO IT!

Otherwise go for it, and ask questions if you need to, just remember i did this a while ago so give me a break!

GL guys


thank you tanky you for this.... sry for the late reply... i have been on vacation for a week up in mammoth... no computers which was actually really nice. '

i may have to stick a thermal probe on one of my vram chips and try the mem mod!

ALSO when you say a VR you are saying a voltage regulator... i think your trying to saw a potentiometer right?

WOW i have lost my touch at typing in the past week.

[four4875]

VR = variable resistor.

[nd4spdbh2]

ohhh ok.... so a potentiometer.... i just thought he ment a voltage regulator..... i may have to do this mod today.

[four4875]

i have a problem with my stock amd hsf i have on there. it dont want to sit flat on the core. im gonna try putting more tension on it, but ive jsut been bending the card, so im going to stick in the backplate thingy that was on stock cooler, i dont know why i didnt do that in the first place. then i can crank the **** outta it and make it nice and tight. in my p4 board i dont have nough room to keep the stock amd fan on, so i put on a couple 5v 40mm fans from allelectronics. at 12V they scream, at 7V im hittin like 73 load, if i push on the hs it drops to like 65, so im thinkin if i get good contact ill be set.

[nd4spdbh2]

so true.... good core contact is key... my card is quite bent from all the pressure... im thinkin of making a lil aluminum bracket that runs the length of the card to keep it from bending but i do have really good core contact.

[four4875]

with that simple little chunk of metal thrown in, its runnin 60 load, at 624 core 1250 ram, i need to get some sinks on the ram and do the vmod for it and see how far i can push them.

rthdribl will artifact a tiny bit (few flashes a second) but doesnt seem to get any worse as it heats like it does, i guess its just hitting its max temp right on that line, prolly more mhz make it worse, i havnt tried. i want to keep putting Vs to it and see how far i can take it, but i dont wanna get greedy and kill it.

if you go to any effort makin somethin, i would say make something to go between the 2 mounting holes on the HS, and put a thermal pad or somethin nonconductive and squishy in the middle to apply pressure directly behind the core. when school starts back up i might end up milling out somethin to replace the stock one, its springy and bends so the ends are hittin caps, i figure i get somethin a bit stronger ill get even better pressure, maybe a little improvement in temps.

[nd4spdbh2]

ahhh i c... well my bday is comming up soon... i got my dad with the OK for a new computer... can you say C2D 6700 + 7900GT + some DDR2 800..... OR if i am lucky my Uncle will buy a new Mac Pro (*DROOLS* 2 3.0ghz 1333FSB woodcrest Xeons) and i will recieve his "cheapie" X2 4200 and 7800gt...

[damarble]

I got a stupid question. What do you mean when you say "shading the resistor"? What is shading exactly?

[four4875]

shading is basically going over it with a pencil.

the graphite is conductive, so as you build up a darker line on the top of the resistor, you lower its resistance. the darker you shade it, the lower the resistance. its a crude way of doing it, and can get changed if its rubbed off or whatever, and isnt exactly accurate. this 6600 mod is actually the first time ive used a pencil to mod a card with caution (last one was a GF2 ti200, i just blindly shaded it and prayed the card would die. it didnt die, but it did get a bit of improvement on the clocks. ive noticed that its hard to get the resistance right on where you want it, one line makes it too low, rub a little off and its too high, try to go another line and its too low again... :bang head

[damarble]

I see. So then the only way to know how far you've gone is with and ohm meter. I may as well give it a shot. This card that was $200 just a year ago is now worth $50, so no big loss if I screw up.