ATI 4850/4870 voltmod thread

[ceemic]

JULO, this single-turn potentiometer is very bad choice. It's too unstable and slightest movement equals dangerous Vgpu jump. You should replace it with multiturn trim-pot.
Also the Vmod soldering points should be secured with hot-glue or electrical tape etc.

But otherwise good job.

[JULO]

Ok, thanks

Vgpu jump doesn't bother me.
But if it is unstable I'll replace it for sure.

[CL3P20]

A few shots of some reference 4850's I completed for a friend...still on air atm [he is waiting on water badly ]

Reference Diamond 4850's: completed GPUv and vDDQ + 3x GPUv output caps and 1x vMEM output cap



Vantage run on stock cooling:


..and a few of my green PCB Diamonds...and '06 run in Xfire

Non-reference PCB, Diamond 4850's: GPUv and 3x GPUv output caps

[Oese]

nice work

[drizzt5]

that's 940mhz @ 1.35V

gj

Could you take it over 1000?

[eKo_]

Good day!
Whether and it is impossible to unblock somehow ROP on videocard PowerColor 4730 PCS?
Sorry for my bad english (

[Theorw]

Good day!
Whether and it is impossible to unblock somehow ROP on videocard PowerColor 4730 PCS?
Sorry for my bad english (

No!

[eKo_]

No!

It`s bad... Thank`s for the answer

[|Oc|REvO_HsArC]

Here's something strange.

My 4870x2 will show artifacts at 850mhz with Vgpu above 1.30v

But its clean and stable with vgpu at 1.29v. But it wont clock higher than 850mhz because vgpu isn't enough. Its watercooled. Temps don't go above 45º.

any thoughts?

[Theorw]

Here's something strange.

My 4870x2 will show artifacts at 850mhz with Vgpu above 1.30v

But its clean and stable with vgpu at 1.29v. But it wont clock higher than 850mhz because vgpu isn't enough. Its watercooled. Temps don't go above 45º.

any thoughts?

Well it seems thats your card OC potential!
100mhz more on a double chip card isnt a little you know!Also the volts are quite increased!

[|Oc|REvO_HsArC]

yeah although I never experienced artifacts due to just higher voltage. Usually artifacts means you don't have enough voltage for a given speed/temperature.

I can do 850mhz 1.29v but not with 1.3xv

weird

[Theorw]

yeah although I never experienced artifacts due to just higher voltage. Usually artifacts means you don't have enough voltage for a given speed/temperature.

I can do 850mhz 1.29v but not with 1.3xv

weird

Well @1,3x volts your VRMs might be hitting their limits and providing less that 1,29 so there u go!U dont have enough current...
At any rate,the VRMs are not designed for 1,3volts so consider yourself lucky for 1,29 and 850mhz!

I had some issued too with my 4850.it could do 830 core @1,32 but @1,39-1,40 it would artifact the hell!!!!!!!In the same speed!
So its not uncommon!

[MetalX]

Anyone perform these volt mods on an Asus EAH4870 1GB? My PCB looks different than the one pictured. I'm still looking through the thread to see if this card has been mentioned.

[CL3P20]

If you can ..post a few good macro pics of the backside of the GPU. I can locate the mod points for you, if you are unable to find any info on the PCB type.

[MetalX]

Thanks man, let me see what I can do.

No camera but found this on Google:




That's a 512MB Top but it I believe it is the same PCB as my 1GB.

[Ruma]

Even though 5 series from ATI is out I think we can get some extra juice from HD4870. With the help from some posts of this thread that's what I did.

My goal: Upgrade from a Hd4870 to a "Hd4890" (gpu= 850mhz) with max vgpu= 1.35v


Here's my contribution to the thread:

The card – HD4870 Golden Sample 512mb:




Cooler off:



The voltage regulator ( NCP5388 )



Since I'm not using the small fan's header I'll use this for ground.

I will also use a fan header to place the VR so I can activate/deactivate the mod whenever I want:



Putting the 100kohm VR mod on and without it’s mod off



Soldering done, ready to put the cooler:



I’ve putted all in the front of the pcb so the wires would be discrete behind the cooler:

[Ruma]

This card has 2 fans, one 80mm pwm and a 70mm fan that’s always on full speed and so it's a bit noisy

I’ll be replacing them with 2 Arctic Cooling 80mm PWM fans connected to the same header.

The heatsink it's good enough so with the new fans it will be a kind of an improvised arctic cooling twin turbo

The wires are too long, reducing to the right length:



I’ve putted a light red sleeve to match ATI’s theme:



Fans attached:



Mod done:



Card mounted inside case:




I decided not to put a molex for the readings so I'v attached a small probe for that:



And tested with Furmark:




I've flashed the bios with a new profile for this fans.
This 80mm not slim fans (opposed to the majority of aftermarket coolers that use slim fans) are very quiet even at full speed.

[Theorw]

Nice job!!!

[Ruma]

Some measures that prove that ATI it's not as hot as some people say.

Unfortunately we can blame the stock cooler, in the stock cards ATI could have done a better job with the cooling but nothing that can't be easily fixed

Ambient Temperature: 23º

Idle:



Load:



3D Mark Vantage (Q6600@3.4ghz / HD4870@850/1000):

[Mic43]

Hi!
I have a reference version of Saphire 4870 with Accelero S1 + two 120mm fans. I have a question. With is better for VRM section - to use original red plate with Acccelero or remove it and cool VRM and RAM with other heatsing?

[Larvitar]

Hi, guys!

I'm with a HIS 4850 IceQ4, that uses the uP6201BQ of the reference PCB, but the sub-serie is "VLP896", and the structure of VRM is different. Well, a picture speak more than thousand words:




There are ways to do pencil mod?

Thanks!

[mib]

Does anyone know how to make Vmods on Asus 4870 Glaciator PCB? This PCB got 4+2 phase.

[Benji Tshi]

Hi guys,

I have a HIS 4850 IceQ4 here, and the PCB is slightly different than reference one (and mine is closer to reference board than larvitar's one :p). Does anyone know if the mods are working on it or if i need a special one ? Thanks.

[zorro2010]

And what maximum voltage is ok for 4870x2? Wouldn't degradation of videochip behins on 1.5?

[bronco113]

A few shots of some reference 4850's I completed for a friend...still on air atm [he is waiting on water badly ]

Hi CL3P20, what a nice work!!!!

Can you please tell me what is an "output cap" and how do you use them on those 4850?

I'm thinking about volt-modding mine, and I've just seen this 3d...

Thanks a lot