# Getting even lower voltages?



## Snigel (Oct 22, 2006)

I've succesfully downclocked my ATI X1800XT, gets nice and low temps especially since I undervolted it. 
I want to undervolt my memory even more, is the limitation in the application or in the card?
Currently I can't go below 1.785v


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## JC316 (Oct 22, 2006)

WTF for?!? Don't go down too far, I hear it's possible to damage your card by going too low.


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## Azn Tr14dZ (Oct 22, 2006)

He wants to do it so there's less heat, but I'm not too sure if it'll damage it or not.


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## Pinchy (Oct 22, 2006)

Ive heard of a card frying due to serious underclocks


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## ace80 (Oct 22, 2006)

I would say the limitation at the mo is the app, coz thats the only range u have to play with, the card will have a limit aswell but how low is anyones guess.
I agree with JC tho, i also heard that unvolting can be dangerous, as in non repairable/dead


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## Snigel (Oct 22, 2006)

If somebody know that low voltage will kill the card, please post some decent facts instead of "I've head somewhere..." High voltage can kill your card too, but that's up to me right? 

If it's a limitation in the application, then it would be really nice for me to do this. 
So far I've lowered my idle temps with 20c


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## ace80 (Oct 22, 2006)

After searching lots of other forums the lowerst i've seen anyone undervolt the mem is like u 1.785v, so until an app comes out that gives u a greater range to use i'm afraid thats it.

As for how low the mem will actually go, i found this on samsungs website(see attached) - spec sheet for GDDR3.
I'm guessing but is the default voltage around 2.0v? My interpritation of the chart is its safe to go +/-0.5v, so min. 1.5v and max. 2.5v


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## JC316 (Oct 22, 2006)

Read here, first and then 3rd page.  http://forums.techpowerup.com/showthread.php?t=17327

This guy had it happen to him.


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## Snigel (Oct 22, 2006)

JC316 said:


> Read here, first and then 3rd page.  http://forums.techpowerup.com/showthread.php?t=17327
> 
> This guy had it happen to him.



Let's see, I see that he got his card severly underclocked and the screen messed up, later on it died. It didn't die due to low voltages but to very low core clock. I've already got a low core clock and are fully aware that there is a bottom limit as well as a upper limit. 
Usually the card don't even underclock when you press find maximum core, so it's possible that something was wrong with the card even before this happened. 
I can also see that somebody "has heard" that the card can die due to low voltages. 
Well if it happens to me, I will be the first to let you know that I killed my cards due to low voltages. Then you will have a more reliable source. 
The topic in that thread were low clocks=dead board, not low voltages=dead board. In this thread we're speaking of voltages.

It seems like a lot of people have missed it but internet forums aren't good source for all information very much are just random guesses and rumours. People will more than gladly spread rumours without having a clue if it's for real or not. 

Underclocking is as much of an art as overclocking. You can't just put the sliders in the bottom and press apply, you have to fine tune your card, check for abnormalities everywhere, use overlay, use multiple monitors, do stressful 2D of all sorts. 
When you go 3D, go there in steps, don't just go from bottom clock to maximum clock. 
Currently my X1800XT is idling at under 40c, no fancy cooling, just a Accelero X2 at 45%



ace80 said:


> After searching lots of other forums the lowerst i've seen anyone undervolt the mem is like u 1.785v, so until an app comes out that gives u a greater range to use i'm afraid thats it.
> 
> As for how low the mem will actually go, i found this on samsungs website(see attached) - spec sheet for GDDR3.
> I'm guessing but is the default voltage around 2.0v? My interpritation of the chart is its safe to go +/-0.5v, so min. 1.5v and max. 2.5v



Thank you very much, informative and probably you're right about the 1.5v. If 1.5v is within specs you could probably go even lower at low memory clocks. Reducing to 1.5v from 1.785 would probably reduce the heat by 20% from on the memory.


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## JC316 (Oct 22, 2006)

Mkay, I just remembered reading that and I thought you might like to know.


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## ARTOSOFT (Oct 23, 2006)

Guys, guys.

Let Snigel try and found out if low voltage can kill or not.

Regards,
Arto.


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## Pinchy (Oct 25, 2006)

lol we can only 'hear' stories about ppl frying cards due to undervoltage because im not gonna go undervolting my card...


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