Introduction

In this article I'll run you through the steps of ramping up the voltage on your X800 (Pro/Pro VIVO/XT/XT PE). As always, the familar warning of "This will void the warranty" and "We take no responsibility of any kind should you damage your video card" applies before we start. Remember to take your time and don't over do it. You should seriously consider replacing the stock HSF if you plan to crank high on the overclock . Check out our GPU Heat Sink Fan Reviews here. Also, should you have any questions or information you wish to share, please post them here.

Before you Begin

I'd like to make clear a important side note before you begin. In regards to "How hot is too hot?", I see and receive this question a lot. First I want to post ATI's official X800 GPU temp specs.

Thermal Parameter Value	temperature
Maximum recommended ASIC case (or center of die backside for flip chip)	105°C
Absolute maximum rated junction temperature: TJmax	125°C
Minimum ambient operating temperature	0°C

Some interesting numbers to say the least. Having posted the info which should provide you with a base to which to compare your temps too, ie 80°C and even 90°C is still within specs. But having said that I'd like to share some words of wisdom from one named ViperJohn

ATI says 95°C is okay but it may not run clean either. I had an ASUS XT-PE that ran at 80C stone stock in the 3DM01se Nature torture loop. While they say it is okay there is a catch to running hot.
For every 10°C you increase a discrete parts (memory chips, cores, Mosfets, IC's, etc) average operating temperature you cut its lifespan in 1/2 what ever that given lifespan may be. Conversely for every 10°C you lower the average operating temperature you double the parts lifespan. It doesn't take a rocket scientist to conclude that a card that runs 60C will have an average life span that is 4 times longer than if the same card runs 80°C.

The above is the reason that a properly modded card can have a longer lifespan that the same card will stock.

John

So before you put the juice to that piece of hardware keep those words in the back of your mind.

Max. safe voltages

Since most people prefer the pencil method, I'll start with that vmod first and come back to the resistor vmod.