ATI X1900 and X1800 Series Overclocking Guide

Howto by Ahmad @ 2006-05-05

You may think you are experienced, or have overclocked before and therefore may think this guide is of little use to you, but I would have to say that you are incorrect. This guide is for both the experienced and inexperienced overclockers. Some parts may be boring for those experienced in the art and they may skip to the highlights and key points of performing this task.
  • prev
  • next

Using ATITool

Using ATITool

Madshrimps (c)
ATiTool main window

The first thing you must do now is to create a new “Default” profile in ATITool. Unfortunately any profile name that begins with Default is reserved, but you can call it anything you like (e.g. “DefClocks”, “DefSettings” etc). Once this profile has been created, you must now set the 3D voltages for your card.

Navigate to the voltage adjustment feature of ATITool (Settings > Voltage Control) and increase your VGPU to 1.425v (remember, this is the default voltage of the GPU under the 3D mode). Save the voltage settings to the profile you created.

Now go back to the main screen and manually type in your video card’s 3D frequencies in the appropriate box (for example, if you have an x1900XT, under “Core” you would type 625 and under “Memory” you would type 750).

Now select the new profile you created and click “Save”. Now you have a profile that contains your correct 3D mode settings. You may choose to let ATITool run this profile at startup if you have disabled ati2evxx.exe just so you get the right performance from your card (otherwise your card will operate at 500MHz/600MHz).

You may also choose to manually configure your x1900’s fan speed from ATITool, which you can include in your “default” profile. You may experiment to see what fan speed is optimal for your setup (for stock clocks, GPU temperature should not go above 65-70 degrees C).

Now I suggest you run 3DMark05 or some other benchmark so you get an idea of what your “stock” (default) scores are.

Madshrimps (c)Madshrimps (c)Madshrimps (c)Madshrimps (c)

When running games/benchmarks the video card will heat up quickly, having proper (case) cooling is advised ->
  • prev
  • next
Comment from aqlumen @ 2006/05/10
After you overclock with with ATI Tool are you still able to play a video?

I've tried using the method (with different voltages and settings, of course) on my X1800XT but when I push the core above 640, video locks up--whether using WMP or MP Classic.

None of the reviews I've seen ever mention playing video after all the overclocking. There's an open debate on this over in the Rage3D forums.
Comment from jmke @ 2006/07/07
just a warning to always keep an eye on your GPU core temps while overclocking, if it gets too hot, you might cause permenant damage
Comment from PsyBorg @ 2006/07/07
I wrote to ATI about some Crossfire difficulties I was having, and they suggested that the problem was I had dual 12V rails. They told me that I needed to have a single 12V rail with over 25A. I have a total of 36A over the dual 12V, so would I have to combine the rails, or would a single work? Also, I can't find a splitter for the PCI-E Power cord, an 8-Pin Splitter so I CAN use a single rail. Any suggestions?
Comment from Gamer @ 2006/07/07
I needed to upgrade a 550watt high power supply to get these cards to work overclocked.
I also had 36Amps ( I think) on the 12 volt rail, but it didn't work.
A Zippy 700 did the trick.

upgrade your PSU.
Comment from PsyBorg @ 2006/07/07
I've got an Enermax Liberty 620W. It should be working fine with Dual 12V/22A for a total of 432W/36A
Comment from Gamer @ 2006/07/07
yonah setup with Crossfire needs 500watt to opererate in non overclocked state, has been tested here.
Comment from PsyBorg @ 2006/07/07
its a 620 Watt PSU minimum power, with a max of 700W. I meant that exclusively over the 12V Rails there is 432 Watts availible. Here's the stats:
Comment from jmke @ 2006/07/07
single 12v maxxed out at 22A, simply not enough
Comment from PsyBorg @ 2006/07/07
Is there a way to combine the rails? Or do I have to get a new PSU?
Comment from jmke @ 2006/07/07
no I don't think you can combine them unfortunately
Comment from PsyBorg @ 2006/07/07
Can you suggest a PSU that would work? I need at least 600W. -_- that PSU was new too...
Comment from jmke @ 2006/07/07
Originally posted by Gamer

A Zippy 700 did the trick.
and Silverstone 700 also worked fine in tests; there are also high rated PC Power&Cooling models available...

as long as it has 30A+ on a single 12v line
Comment from Carni4 @ 2006/07/24
Nice guide.

I was putting a rig together for a friend of mine (he fried his old P4 setup ) with a x1900xt card and an amd s939 3700+/4000+, 2gb pc4000 ram, 1 sataII HD.

We were thinking of an Antec Performance TX1050B case which has a Smartpower 500W PSU.

Will this be enough for stock speeds? No OC. Website says it only has 17A @ 12V line...

My guess is it wont work...
Comment from piotke @ 2006/07/24
Will work.
Comment from jmke @ 2006/07/24
will work, but not much for extra hardware
Comment from Rutar @ 2006/07/24
it has two 12V rails and 500W total, that should be enough for non CF/SLI systems