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post #21 of (permalink) Old 05-24-2018, 11:13 AM
Minium
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Quote: Originally Posted by mllrkllr88 View Post
Hey

Not sure I completely understand the question, you should reference a specific card so we can look deeper. I have seen a few very gold cards, like 6600GT for instance, that use linear regulators for things like memory. So on a few very rare old cards its not possible, however, most cards I have come across are using a buck converter style power management which means you should have the ability to adjust voltage in real time.
I found a PCB breakdown from buildzoid for a R9 290X, the card actually uses one single voltage controller and has two voltage sense pins, one for vcore and one for vmem. I didn't find any information about voltmodding both vcore and vmem if both voltages are controlled by the same controller, and wondered how people do it. It seems such x+x voltage controllers actually have two sense lines so its actually really easy.

Another question I have is how do people find the the FB pins without having the datasheet for a voltage controller ? How do you do it if you dont have access to the datasheet ?
I just ordered some potentiometers,disable switches and voltage displays to do my first practice voltage mod on an old 8800GTS, there is a datasheet for the memory voltage controller so I know where the FB pin is but there is no public datasheet for the core voltage controller and I only know where the FB pin is because some people on the internet found it, but how?

Because I want to do some DryIce overclocking on cards like my 980Ti, not knowing how to find the FB circuit would be a problem. My 980Ti uses an uP1984A and there is literally no information about it anywhere. There is a uP1983 with the datasheet available to the public but the pinouts are completely different (checked with a multimeter) so I would need to find the FB pin some other way.

Thx for sharing all your knowledge about voltmodding with this thread
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