ATI 4850/4870 voltmod thread

[jason4207]

haha, i guess that works too.

so, just to make sure i get this right. Im trying to make things as clear cut for me, and any one else new to this. I've made a clean schematic labeling everything that needs to be done, and all of the measurement points. Can you let me know if i am missing anything or messed up on anything.

The is the main area.




The full image is available HERE.
The base picture i used i obtained from TechPowerUp from THIS article.

I think you have the wrong spot. You can see the trace line on the board if you look closely. Anywhere along the trace line is perfectly fine. I actually bridged two points along the line for a stronger connection. All points along the trace are electrically the same point.

It's a good idea to take resistance measurements before, during, and after you install the mods. Then you can see if your readings are matching up w/ what everyone is posting.

I'm in about the same position as wesleyclark, which is i'm about to mod my first card (4850)!!! And i have a few questions. First jason4207, how can you put the middle pin of the blue vr into the fan connector since it isn't in the same line with the other two, and second do i have to use these very small cables (which i don't know how they called and where to find them) you used in your mod or i could use the cables that the fan connector had?

Is the yellow spot that wesleyclark posted right? cause i have read that the right spot is this one
or maybe both can be used?

I would like to thank everyone for the help and the info you provide us.

All 3 pins on the VR's I have slide perfectly into a 3-pin fan connector. I'm not sure what you mean about them not lining up.

I have found that if you don't use smaller cables your mods are much more likely to pop off, and you are going to have heat the components more b/c the thicker gauge wire will wick heat away quickly. I use 30awg wire for the VR's, and 18-22awg for the read points. I hand crimp, and solder all my connections.

I am also curious. That would make my VGPU mod much much easier..

Edit. Also, I am curious. What is the max Voltage I shoudl apply for the memory. I am at 2.07 right now at 1100mhz using the stock cooler. Thanks.

I've heard anywhere from 2.1-2.2 is a safe max, but I wouldn't consider pushing it until you can get aftermarket cooling. The stock HSF puts a lot of additional heat on the RAM chips from the GPU.

Hi, 1st post getting Asus 4850 in a mail tomorrow, planing to put Maze 4 on it and OC it to 800.

Quick question, what voltage do you need for 4850 GPU to reach stable 800MHz. Also is it possible to reach 800 MHz trough BIOS only or Vmod is needed.

Thanks.

Not sure exactly what voltage you'll need, but I think BIOS editing will only get you to 720-750MHz.

who has done the pencil mod? how safe is it? just a regular # 2?

is there a way to check voltage in windows? i dont have a multimeter lol

You need a DMM to even consider doing this. They are a lot cheaper than a new gfx card.