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Old 04-08-06, 08:00 PM   #2
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Join Date: Mar 2004
Location: Scotland
Posts: 568
Default Re: BFG 6800GT OC core voltage is what?

Originally Posted by c_chekay
okay Ive been reading old posts and Im allittle worried, every post Ive been reading no core voltage goes over 1.5 well Im running at 1.6 (according to RT) and this is a pure stock unit. BTW I put a voltmeter on the regulator directly and checked it directly to make sure its 1.6 and it is. Now recently Ive been having issues with my computer while playing intense d3d games the computer just flat out shuts off and then reboots itself and then hangs on the reboot. Now its not (far as I can tell) any temperature issues. Im running full stock BFG OC settings. 370/1000

RT report

Now I would like to start OC'n but the voltage and this crappy heatsink are my issues at hand. (nip at the bud no liquid coolers) Now 1) if this voltage is way too high what should I set it at, and how? 2) anyone finally see a after market cooler for the 6800 series cards besides the liquid cooler. or know how to modify the fan's on the heatsink so I can get some REAL CFM flowing thru the card? I have allready planned on modifying the fins on the heatsink so they have a knife edge for better flow but the fans themselves are just horrible low CFM and noisy bastards.

Any help is appreciated thank you.
First off, if you read old posts properly then you would know that RT doesn't measure volts --> it translates stored binary data. Which means that RT doesn't actually know what core volts your card is supplying.

Also, the built-in bios selectable core volts options for both 6800gt and 6800Ultra cards are, 1.1v, 1.3v, 1.4v and 1.5v. So anything outside this range can only be got by hard modding the core volts regulator directly on the card.

The standard 6800gt core volts of 1.3v should easily allow an overclock to 400 plus levels. However the max available will obviously be influenced by the quality of heatsink fitted to the card. So better results will be got by replacing the not so good stock heatsink with something like an Arctic NV5 silencer (which is my preferred option), or maybe a Zalman type solution?

And setting core volts above 1.3v is not recommended unless using water cooling. Also, at levels of 1.4v or above, it then becomes much more important to keep a wary eye on the regulator (vrm) component temps. The core/memory regulator design, including typical quality of components used, has always been a main weakness against extreme overclocking of a 6800gt.

It should always be remembered that the higher core volts options were really meant only for the 6800Ultra version of card. Which not only had better heatsinking, but also used more robust core/memory volts regulator designs and components.
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BFG 6800GS (16x1,6vp) @ 300/430/1200.

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