I finished the 9800XT GPU voltmod but..........

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cornelious0_0

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All right, as the thread says, I have finally finished the voltmod to my XT's GPU.....and it looks great. I ended up going with a 10k pot as that was all I could get my hands on. The problem now lies in measuring the voltage/resistance properly so that I don't do any damage to the card.

As we speak I'm looking at my multimeter, trying to figure out how to measure the resistance properly. Under the Ohms section I have the following options: 200, 2k, 20k, 200k, and 2m. If I set it to "200" and check the XT (yes in the proper spot) the multimeter reads about 11.2. Is this 11.2k??? I am not looking to go any higher then 1.8v or so on the card and I REALLY need to know what I should be reading with the multimeter in order for this 10k pot to give me 1.8v or so. I would really like help with this if anyone has an answer for me.

In short..... 1) am I reading/setting the multimeter correctly? and 2) what should the multimeter be reading for me to achieve 1.85v?
 
those settings on the multimeter do nothing but determine the decimal places on the readout. so the proper setting is 2k for anything below 2 volts. Set it to 2k and measure the volts and report back. You can't measure the resistance of the pot once it is hooked up on the card. This is because after it is hooked up, you are measuring the resistance of the entire circuit, or something like that. Just set the pot at its maximum resistance, boot up, measure the voltage (should be basically stock) and slowly increase the pot .5 to 1 turn at a time and measure the voltage after each turn. Go slowly. And if it locks up, turn of the pc, crank the pot back down some, and go up slower. Take your time and its pretty hard to screw up. Oh, if you live with other people LOCK YOUR DOOR. My sister came in on me and I didn't hear her when I was adjusting the volts to my radeon and when she talked I literally jumped cranking the pot like 5 turns. HArd lock. Lucky it wasn't permanent.

So basically, set the multimeter to 2k setting and there is no way to exactly sure what resistance you should get to be 1.8v unless you unsolder the mod to get a reading of just the pot.
 
The way the volt mod works is that the chip you are connecting the resistor to is tricking the chip into thinking there is less voltage going to the chip, and so it increases it.

You want to start with the resistor all the way to the highest resistance, this should give the standard voltage because no voltage is being leaked. You definetly need a voltmeter, measure in volts, not ohms, resistance will vary from card to card.

There is a certain spot on the card to connect the red probe on the volt meter, the black wire connects to your case.

I attached a red wire to the volage measuring point just so it was easier to measure voltage, you should never change the resistance without a volt meter measuring voltage.

rad2.JPG
 
Originally posted by computerpro3
those settings on the multimeter do nothing but determine the decimal places on the readout. so the proper setting is 2k for anything below 2 volts. Set it to 2k and measure the volts and report back. You can't measure the resistance of the pot once it is hooked up on the card. This is because after it is hooked up, you are measuring the resistance of the entire circuit, or something like that. Just set the pot at its maximum resistance, boot up, measure the voltage (should be basically stock) and slowly increase the pot .5 to 1 turn at a time and measure the voltage after each turn. Go slowly. And if it locks up, turn of the pc, crank the pot back down some, and go up slower. Take your time and its pretty hard to screw up. Oh, if you live with other people LOCK YOUR DOOR. My sister came in on me and I didn't hear her when I was adjusting the volts to my radeon and when she talked I literally jumped cranking the pot like 5 turns. HArd lock. Lucky it wasn't permanent.

So basically, set the multimeter to 2k setting and there is no way to exactly sure what resistance you should get to be 1.8v unless you unsolder the mod to get a reading of just the pot.

Thank you, that really does help. My one other question is how I should tell if the pot is at it's max resistance. Is there a way to find out/do it without removing it from the mod? It isn't that big of a deal if I have to take it off but I'm just wondering. Sorry for the dumb sounding questions but I really wanna get this right.

Thx again, I can't get wait to get playing with this thing..........and then get the droop mod done tomorrow to have some more fun. ;) :p
 
you might be able to check the resistance with the card off, does your voltmeter measure ohms? if you, plug it up to both ends of the resistor while the card is off, if you get 10k ohms, it is all the way, if not turn it all the way the other way.

Also sometimes the pots say on the side which way to turn it, probably not it your case, you'll just have to measure it.
 
you wont be able to get an accurate resistance reading of the Pot with it attached to the card, since the circuitry of the card is going to add resistance.

stock voltage on the XT is 1.8V, so i have no idea why you even bothered modding it if you dont wanna go over 1.8V? :confused:
 
Originally posted by Stang Man
you wont be able to get an accurate resistance reading of the Pot with it attached to the card, since the circuitry of the card is going to add resistance.

stock voltage on the XT is 1.8V, so i have no idea why you even bothered modding it if you dont wanna go over 1.8V? :confused:

From what I've heard and seen, stock voltage on the XT is NOT 1.8v but actually about 1.4v or so. I trust the guys over their with this stuff, as that is where most of these mods are "born". I was kinda hoping that someone here would be able to help me though. Computerpro???
 
Corenelius,

I'd never thought you'd do something like that to your card,....good job man...................goodluck to your 9800xt still..so what kind of cooling you using now these days......



henessey
 
Originally posted by henesseynalert
Corenelius,

I'd never thought you'd do something like that to your card,....good job man...................goodluck to your 9800xt still..so what kind of cooling you using now these days......



henessey

Yeah, I guess I kinda have labaled myself as a bit of a "safe guy" with my stuff up until now. The soldering went great and it looks awsome.....but I just need to get this one final thing out of the way. Using the 10k pot I've got on there I have voltages from 1.6v up to 2.2v available.....up from the stock 1.4v.

What would be ideal is if someone could tell me if I could just turn it "x" amount of times either clockwise or counterclockwise.......then I could just sit there and turn it a certain way about 50 times and know that it'd be down to 1.6v.

BTW, I've got the Tt Giant III on my XT with some nice temps going right now. I have recently modded it by removing the section of aluminum taht the blower fan is attached to normally, allowing my 85cfm intake to blow on the ramsinks underneath. Tomorrow I'm going out to pick up a Vantec fancard and I've got an old 60x15mm from my 1GHz Duron cooler that I'm gonna attach onto the back plate to help get rid of the heat on the back.....which is where the heatpipes take it all.

I woudl REALLY appreciate it if someone could tell me if there's ANYTHING I can do to get it to the point where the pot is having no effect so I can boot up. Wouldn't it just be a matter of turning it one way enough times? Clockwise or Counter Clockwise???

thx again, I'll ahve results from the droop mod in tomorrow after I get back with teh 50k pot.....and then my fun will begin. ;)
 
Originally posted by cornelious0_0
From what I've heard and seen, stock voltage on the XT is NOT 1.8v but actually about 1.4v or so. I trust the guys over their with this stuff, as that is where most of these mods are "born". I was kinda hoping that someone here would be able to help me though. Computerpro???

whatever.:rolleyes:

stock xt = 1.8V
 
Originally posted by Stang Man
whatever.:rolleyes:

stock xt = 1.8V

Just keep tellin' yourself that.....I suggest you go check out xtremesystems yourself to see what being hardcore is REALLY about. ;)

I'm still waiting to see if anyone can lend me a hand.....which way do i turn it to lower the voltage? I'll just turn it all the way for my pot and sit .2v above stock at 1.6v if it means i can at least get on my comp.
 
No hard feelings Stang Man but check it out for yourself.

Oh, and here's an exerpt from the first page:

Here's more information on the 9800XT Vgpu vmod. As mentioned above, the 5240 controller has 5 voltage select pins, VID4-VID0. The 9800XT has them hardwired: VID0,VID1 and VID4 are grounded and VID2 and VID3 are high. This normally gives an output voltage of 1.40V. However, unlike the example circuit in the data sheet, the 9800XT has a resistor between pin 17 and pin18 (VcoreD and Vcore+), as well as the series resistor between pin 18 and the Vgpu voltage. The resistor between pins 17 and 18 results in a voltage drop from Vgpu to pin 18. On the 9800XT the resistor between pins 17 and 18 is R1591 and the series resistor is R1592. The Vgpu voltage is thus:

Vgpu=1.40x(1+R1592/R1591)

The original resistor values are:
R1592= 432 ohms (62A code)
R1591=1620 ohms (21B code)

This give a default Vgpu=1.4x(1+432/1620)=1.77V. The measured value is 1.78V, which is excellent agreement. To increase Vgpu the easiest approach is to reduce the resistance between pins 17 and 18 by carefully connecting a pot across R1591. I'd suggest using a 20K pot. When the pot is at 20K, Vgpu would be 1.80V. The pot would be at 7.9K for 1.85V and 4.8K for 1.90V. If you want to go above 1.90V, a 10K pot might be a better choice.
 
corneious there are ways of telling which way to wind the pot without removing it but i'm guessing (could be wrong) that this is your first voltmod so i'd advise to check it the safeist way which is to unsolder one of the legs of the pot and then check the resistance with in turned fully clockwise and fully counterclockwise, one will read 0 ohms and the other will read approximately 10k. whichever one is 10k set it to that and resolder the leg back.

your card will then be safe to get back in the comp and boot up. from there you can slowly wind in the pot to lower the resistance and increase the voltage but make sure you measure at the correct point and go slowly.

hope that helps, any more q's just ask
 
You would be correct in guessing that this is/was my first voltmod.....but I'm glad it went well.

I do have one question though.....does it matter which leg I "detach" from it's wire? right now I have R1597 wired to the middle leg, and R1592 wired to the right side leg.....which one should I leave hooked up?

Thank you for all your help, I'm thinkin' that once I've got this one last thing straight I'll be good to go. ;) But, I'm just thinking.....shouldn't the way you have to turn it (to increase or decrease resistance) be the same from pot to pot?
 
K, well, I have decided to just go pick up a 20k pot tomorrow. a 20k will "top out" at 1.9v, and to go any higher then that I'd have to do a second voltmod so I think I'd just end up staying at 1.9 anyways. An added bonus is that with a 20k pot I am at no risk of dmging or overheating my card, which will kind of "ease the tension" when I go to hook it up. :)

For now I'm just gonna disconnect the pot and cover up the wires so I can at least have the card in my comp 'till tomorrow.

thx
 
so what are the improvements.. ?

Also one more thing corny.. how is the 2.8C hangin' I got my M0 to 3.5 w/ 1.55Volts.. how many volts are you pumpin for the great overclock you have?

And that ram is insane (awesome scores too ;) )

Anyways, is a voltmod worth it? That is what I want to know coz I want to do the same to my card too!

p.s. when did you get a 2.8C I thought you had a 2.4C @ 3.3 :confused:

Let me label you the hardware whore! :p
 
Originally posted by KickAssCop
so what are the improvements.. ?

Also one more thing corny.. how is the 2.8C hangin' I got my M0 to 3.5 w/ 1.55Volts.. how many volts are you pumpin for the great overclock you have?

And that ram is insane (awesome scores too ;) )

Anyways, is a voltmod worth it? That is what I want to know coz I want to do the same to my card too!

p.s. when did you get a 2.8C I thought you had a 2.4C @ 3.3 :confused:

Let me label you the hardware whore! :p

Dude, it's so nice to see that you finally ditched that old 1.8 of yours.....good stuff.

*sigh*

I had that card installed with the pot removed last night and it was fine. I shut the comp down, only to come back this morning and turn it on to have the power cut only a split second later.....I think you all know what happened. *sigh* One of the wires had come loose under the card and was loose when i turned it on.....zzzzaapp.

So yeah, umm, I kinda don't have much of a comp anymore I guess. I'll probly just use the cash one of my friends owes me to pick up an FX5200 (i don't really game anyways) until next gen comes out.

Surprisingly I'm not really mad at all.....I guess I just had to learn the hard way.

R.I.P.
 
Cornelious, you're not reading this right...

just because the formula is:
This normally gives an output voltage of 1.40V.

doesn't make the Vgpu 1.4V. that's normally, without the rest of the circuitry of the XT. OF COURSE, that's not gonna happen, cause you've GOT the circuitry, if you didn't, you wouldn't have a card, you would just have a little freakin 5420 IC voltage controller.

the DEFAULT SPEC voltage of the R360 = 1.8V.

the card in particular, had a default of 1.77V (within spec of 5% or whatever it was)

The original resistor values are:
R1592= 432 ohms (62A code)
R1591=1620 ohms (21B code)

This give a default Vgpu=1.4x(1+432/1620)=1.77V. The measured value is 1.78V,

and check my handle at XS, "Stang_Man".. XS/XR is not Hardcore, they're Xtreme. ;)

i've been through the different video card mods, from R200, R300, R350, R360... i've talked extensively with Catch22 about different vmods. the vgpu, the vref, the vdd, vddq, the r1597 mod, etc etc...

i hope this shed some light for you :)
 
Originally posted by cornelious0_0
DuI had that card installed with the pot removed last night and it was fine. I shut the comp down, only to come back this morning and turn it on to have the power cut only a split second later.....I think you all know what happened. *sigh* One of the wires had come loose under the card and was loose when i turned it on.....zzzzaapp.

So yeah, umm, I kinda don't have much of a comp anymore I guess. I'll probly just use the cash one of my friends owes me to pick up an FX5200 (i don't really game anyways) until next gen comes out.

Surprisingly I'm not really mad at all.....I guess I just had to learn the hard way.

R.I.P.

are you FREAKIN serious?? wire come loose??... your soldering could have used some help.

i can wing my cards around by the vmod wires if i wanted too, and they'd stick.

that sucks dude... i feel sorry for ya :(
 
If you want to measure the resistance of the pot put your dmm's leads on the first and second pins of the pot.
| | |
^^
If you put the leads on the first and third pin you will get the maximum readout of the pot, regardless of how much you turned the knob.

I will say this again(as someone else said) you can not have accurate measurements of the pot while it is hooked to the card. Even if you turn the computer off. It doesn't matter because your suppose to measure resistance when there is no current anyway.

Good luck
 
I may be going next gen, I will drop you a line if you want a deal on my card in a month or two.
 
NO WAY!!!!!! oh man that sux! Cornelious, are you sure its dead? I doubt it would died that quick. after all my radeon 9700 pro has survived many shorts including shorting ground to the vgpu pin to pump god knows how many volts through the core, so many that at the post screen there were 1 and 0 completley covering the screen. I have even shorted it while it was on causing an instant hard lock. I suggest removing the mod completley using solderwick and trying the card again. Perhaps even in a different machine. I really hope it hasn't died man, that was a really good clocking xt.

Hold on a sec....I'm confused. I thought you removed the mod....how did the wires come loose?


edit: oh yeah, cornelious, stang is one of the most xtreme overclockers out there lol. He REALLY knows his stuff. He hit 23k with a 9700 pro:eek: and vmods the hell out of everything. He's done phase change, taken an axp to 3ghz, etc. etc. HE's beyond [H]ard.
 
Originally posted by computerpro3
NO WAY!!!!!! oh man that sux! Cornelious, are you sure its dead? I doubt it would died that quick. after all my radeon 9700 pro has survived many shorts including shorting ground to the vgpu pin to pump god knows how many volts through the core, so many that at the post screen there were 1 and 0 completley covering the screen. I have even shorted it while it was on causing an instant hard lock. I suggest removing the mod completley using solderwick and trying the card again. Perhaps even in a different machine. I really hope it hasn't died man, that was a really good clocking xt.

Hold on a sec....I'm confused. I thought you removed the mod....how did the wires come loose?


edit: oh yeah, cornelious, stang is one of the most xtreme overclockers out there lol. He REALLY knows his stuff. He hit 23k with a 9700 pro:eek: and vmods the hell out of everything. He's done phase change, taken an axp to 3ghz, etc. etc. HE's beyond [H]ard.

K, sry, I didn't really mean anything towards Stang Man at all and I don't think it's really relelvant now anyways. ;)

The funny thing is that I had picked up the card by the wires and everything was fine.....so whatever.

What I did was remove the pot and tape up the end of the wires on THAT side. I spose I could try it in my parents computer but I DOUBT that's gonna make any difference. When you turn on the comp the card itself is making a very high pitced whining sound and the monitor never gets any kind of a signal....the light just keeps blinking green.

Dunno, I'm not expecting it to work in their computer but I'll give it a shot.
 
Originally posted by IYIENACE
Good excuse to get a better card lol. ;)

Yeah, we'll see. If they go ahead with the RMA then maybe I'll even get a better overclocker. I have this problem with buying the latest and greatest as SOON as it hits the market.....and I'm thinkin' that since my card was of the "first few" it might have some kind of effect on the OC. One thing's for sure, if I get a new card back from them I'm NOT voltmodding it. ;)

I'm almost tempted to make my way back to Nvidia if the card doesn't come back "approved" and get a MSI 5900XT to have some overclocking fun.....at least until the X800-XT is released. ;)

We'll see how things play out though, they say to allow 10 day for the card to be returned/replaced but you'd think that if they turn it on and it DOESN'T work it shouldn't take too long. ;)

I'll be sure to keep you guys posted. Thx for "feeling for me" on this one.....I'm actually surprised that it's not phasing me in the least. Of course it sux to have no card, but given my history you'd think I'd be bawling my eyes out by now. ;)
 
Originally posted by cornelious0_0


So yeah, umm, I kinda don't have much of a comp anymore I guess. I'll probly just use the cash one of my friends owes me to pick up an FX5200 (i don't really game anyways) until next gen comes out.


Why in the world would you have a 9800XT if you dont play games? Play benchmarks instead?
 
Yea why in the world would you have a 9800 xt if you don't game? That's like buying a porche is you don't even drive.

~Adam
 
Originally posted by CleanSlate
Yea why in the world would you have a 9800 xt if you don't game? That's like buying a porche is you don't even drive.

~Adam

I would really hope that this thread doesn't turn into a mob of people bashing me for my reasons for owning a video card. I do game, just not as much as I used to. Truth is that I just have to have the best.....and I'm gonna leave it at that.

I'm really hoping that the RMA comes through, and it SHOULD be here before or by the 8th, so that I have it for my LAN. ;)

The sooner the better, I wanna get rid of this POS FX5200 I've got in here for a temp. ;) :p
 
Well, at least now I've got some overclocking/benchmarking to do. :p

My new MSI FX5200 makes it from its stock 250/400 up to 345/570 artifact free. ;) Not to shabby for a card that's <$100 CDN. :cool:

Next up..........3DMark. :D
 
really feeling for you corn, on a serious note i hope that this doesn't put you off voltmodding for good. I've had a couple of scares when voltmodding but i keep coming back to it.

and good luck with the RMA as well dude (just waitin for someone to say it's unethical)
 
I'm almost tempted to make my way back to Nvidia if the card doesn't come back "approved" and get a MSI 5900XT to have some overclocking fun

Gotta say, I'm loving mine. The VIVO capability the card brings along is nice!

These cards get much worse rep than they deserve because of their poor shader performance.

Yeah, their shader performance is sub-standard. But in EVERYTHING ELSE they compete with the 9800 nicely. They are really, REALLY strong DX7 and DX8 products....they just fail when DX9 is required heavily.

Their architecture decision was really the problem. nVidia went with 4x2, assuming games would continue to be as multi-textured as they had been in the past. ATI went with 8x1, assuming shaders would take over what multitexturing had provided before.

In multitexturing ops (common in DX7-generation products), their pipeline architecture is essentially identical. The 9800 would require 2 render passes for a 2-texture pass scene, while a GeForceFX could do it in 1. Granted, the 9800 could do it twice as fast, so they tied.

Problem is that in newer games, that only HAVE 1 texture pass...suddenly the GeForceFX is hurting. It basically wastes half its texture units.
 
Well, that sucks. Gonna try a volt mod on the 5200? :eek:

It is unethical, but at the cost of a 9800 XT I understand why he's trying. It doesn't make it right, but I can kinda see where he's coming from.
 
Originally posted by THE JEW (RaVeN)
It is unethical, but at the cost of a 9800 XT I understand why he's trying. It doesn't make it right, but I can kinda see where he's coming from.

like i said, just waiting for someone to say it, i can fully understand why corn's trying to rma it as well, i know i would if i thought i had a chance
 
Well, when he's sitting there burning in hell, or reincarnated as a toad, or terrible fortune karmicly befalls him, or something...

At least he'll know he stuck it to the man once in his past life!
 
Originally posted by fr33ze
like i said, just waiting for someone to say it, i can fully understand why corn's trying to rma it as well, i know i would if i thought i had a chance

Thx for the concern guys.....I really appreciate it. I do realise that it's unethical to RMA the thing.....but you can't blame me for trying. I'm fairly confident that it should go alright, a buddy of mine had a 9800Pro water cooled and when the system leaked he RMA'd it.....and go a new card, no hassle. Visually the card is in perfect shape, and I'm hoping it doesn't take long for them to figure out that it's busted.....as I'm hoping that I'll be able to get my replacement before the 8th of May for a LAN. I won't be devastated if I don't get the replacement but it'd sure be nice, I should even get a better overclocker.

I don't know if/when I might get back into voltmodding but I'm sure as hell not trying it out on the new XT.....that's for sure. ;)

I'm sending the card out tonight, cross your fingers for me. :cool:

On a side note: I have a whole new appreciation for the 9800XT now that I've TRIED to play Unreal2k4 on this POS 5200. ;) Even at 640x480 with EVERYTHING turned off and on lowest detail it's still noticeably slower then my XT was at 1280x1024 with everything cranked. :( Ah well, if anything I'll probly start gaming a little more with the new card.....now that I've seen what it's like on the budget side of the fence. ;)

At least he'll know he stuck it to the man once in his past life!

Heh, thx for that dude.....made me laugh. :D
 
Originally posted by cornelious0_0
Thx for the concern guys.....I really appreciate it. I do realise that it's unethical to RMA the thing.....but you can't blame me for trying.

I hope they dont RMA it. You are pathetic for trying to RMA it in the first place. YOU broke it, YOU pay for it. If you cant afford to lose something trying to mod it, then dont do it. Its pretty simple. People like you make it harder for honest people to RMA and return things.
 
Originally posted by fallguy
I hope they dont RMA it. You are pathetic for trying to RMA it in the first place. YOU broke it, YOU pay for it. If you cant afford to lose something trying to mod it, then dont do it. Its pretty simple. People like you make it harder for honest people to RMA and return things.

I was waiting for SOMEONE to bring it up but.......what are you trying to prove or do by being so outright rude and offensive??? Say what you want but what's done is done.....and nothing you say is going to change my mind. I already said, if they don't RMA it then fine.....whatever, if ATI is actually doing their job then it WON'T get "approved" and replaced, it's as simple as that. However, there are QUITE a few people that DO get new cards sent to 'em after doing voltmods and such so how is it suddenly my fault if ATI isn't doing their job in their own RMA department???

If you ask me, they're costing THEY're the ones costing the company money. I'm paying to ship it to them and if it doesn't go over then fine.....but if it does then there's no reason I should be blamed for their negligence.
 
Originally posted by fr33ze
rma it, thats my say on the hole "should i, shouldn't i" debate.

At least I've got a LITTLE support around here, thx dude. It's going out tonight. It'll take two days to get there and as long as it only takes 'em a few days to "check it out" I'll have my replacement before my LAN in May.....if it goes over. ;)

I'll be sure to let you know as I get the information from ATI.
 
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