Radeon HD 4850 Voltmods

[W1zzard]

Show me something with zero resistance, please

he's probably talking about a wire which is almost no resistance, it will still your kill your card.

 

[yanahs]

yes if your resistance is too low, the voltage will go WAY high and WILL kill the card

so if i use a single piece of wire there is still the risk of killing my card with the first mod? right now i'm getting 1.3v.. any chance i can safely boost it up ?with the first mod?

 

[yanahs]

I don't believe the people with 42-45C load temps. What cooler are you using? Please prove me wrong. I max out at 55C running the ATI Tool scanner with an Accelero S1[/QUOTE]

Im using an Accelero S1 tied two 12cm fans on them.. when i dont use the fans it goes up to 60c.. i only use rthdrblt to test load up my gpu though..

 

[W1zzard]

so if i use a single piece of wire there is still the risk of killing my card with the first mod? right now i'm getting 1.3v.. any chance i can safely boost it up ?with the first mod?

you need to use a resistor as instructed. of course you can have wires leading to each end of the resistor (duh?).

 

[me_martin]

what was your temps before with 1.495v? that L100 stuff is pretty good huh? chemical store or do drug stores have em?

In load my temp was like 80~85C and i think thats to high :S
Presumably the chemical store will have it.

 

[yanahs]

thanx wizzard

 

[yanahs]

In load my temp was like 80~85C and i think thats to high :S
Presumably the chemical store will have it.

wow that is pretty hot.. and that with aftermarket coolers?

 

[kingkongtol]

what the safest temps degree?, im almost 60C, with just pencilmod @750/1175
and, i dont know why my memclock can go higher, beside im just doing vgpu mod, and not vmem mod...

 

[yanahs]

@kingkongtol
I'm not sure about the safest max limit temp.. but i read somewhere that these 4series may run upto 90c to 100c?? but i like to keep mine under 70..

my mem gave me artifacts @ 1150 (during 3dmark06 / cpu test only) when i went down to 1100.. arties were gone..

cheers bro

 

[me_martin]

wow that is pretty hot.. and that with aftermarket coolers?

I got an Accelero S1 R.2 with two 120mm Noctua fans on it, but it couldn't cool down the GUP enough at 1.495v (thats my opinion )

 

[quasar923]

why do i need a multi reader? and if i really really need one where can i get one and for how much?

 

[W1zzard]

you mean a multimeter? any cheap $10 one should do. you need 3.5 digits, 2.5 digits is not accurate enough

 

[DJSUB]

i'm completely noob with this.
i just want to ask what settings to use in the digital multimeter to measure the voltage?
i already killed 2pcs. 4850 because of the pencil modding without a multimeter

how can i measure the idle & load voltage of the card?
is it safe to measure the voltage while benching or doing some stability test to get the load voltage?

sorry for my bad english

thanks!

 

[Drizzt5]

I'm preparing to pencil mod my 4850, I just got done doing a bios flash. I can't clock any higher then I could before (I think I can clock lower) and an unusal thing happened. On load i used my DMM and it said that there was 1.3v's going through the vgpu....

All i did was flash the bios ? I don't think it's suppoused to go that high?

Did I measure it wrong? If I don't have something properly grounded will it measure higher then it's suppoused to? And I'm still on the stock cooler for the moment (my s1 is sitting right next to me, ready to go) and my temps seem good. I don't think I'm measuirng correctly. But I tried all 3 of the vgpu spots that I know of.


Anyone have any suggestions?


P.S. my card is the Asus 4850, and I flashed it using this bios.

3. Asus HD4850 Light Overclocked. DF Core 700MHz Mem 1100MHz Auto Cool Fan.
GPU Core upper Limit 1200MHz
Memory Upper limit 1400MHz
Vcore DF 1.12V

Asus HD4850 Light Overclocked

I'm also using this DMM

And i set it to the 2 for DCV (right side of the dial) :/ If thats the wrong spot then I guess thats my problem there

Thanks in advance.

 

[tomcug]

Drizzt5, I think you should begin with checking your card's voltage with stock BIOS. It's impossible to reach 1,3V with just modded BIOS. What's more, the BIOS you flashed your card with has a stock 3D voltage. I think you've set your DMM to right spot, so this isn't your problem. I always use my case as a ground and it works pretty good, voltage measure is accurate.

 

[Drizzt5]

So I should reflash to my orignal bios then?

If i still have 1.3v's don't you think it's the DMM that I am doing wrong with.

I changed the DMM to 20 instead of 2 so It wouldn't round and I still got something pretty high. 1.29v's vgpu....

 

[me_martin]

wow that is pretty hot.. and that with aftermarket coolers?

Unfortunately yes

 

[tomcug]

Drizzt5, use the stop marked in yellow as a ground. If you'll still read 1,3V, then I'm out of ideas.

 

[Drizzt5]

It was a bad DMM, thx for suggestions. I went and purchased a good one.

 

[pablo NZ]

so if i'm reading this right, I can use silver conductive ink instead of a pencil for pencil-mod #2?

I just prefer ink over pencil as my pencil mods have a tendency to degrade

 

[Drizzt5]

Nice thanks wizard, I'm 780/1000 stable with the first pencil mod. I'm going to take the card out again and just try to squeeze up to 1.32-1.35 vgpu if I can. Right now I'm only at 1.28.

 

[yanahs]

Unfortunately yes

@me martin
I dont suppose I could trouble you for the resistance value of you L100 magic stuff.. so i can compare the resistance values with these alternatives

I'm thinking of some alternatives to pencil with the first mod (just for fun)

1.
http://www.permatex.com/products/au...uick_Grid_Rear_Window_Defogger_Repair_Kit.htm

but as the tds says high conductivity.. i'd rather be safe and get the resitane value first.. adn compare it with your L100

2.
get a small piece of paper load it up with pencil lead, then tape it on the resistor ..

maybe i can get 1.4 with these options..
or can can somone help with the res value needed for the 1.4 bump.. or does it differ from each card?

cheers

 

[Hayder_Master]

w1zzard, i say only one think about guys who using pencil voltage mod they are professionals , and you are one of them

 

[awdrifter]

How low do I need to shade the resistance down to (in ohms) will I get 1.4v on this mod? Thanks.

 

[tomcug]

I've shaded it to 500Ohms and set 1,15V in BIOS to reach 1,4V. That's all you need.