Underclocking a 6800:would it damage the gpu?

They make noise, too.

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atomidude
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Underclocking a 6800:would it damage the gpu?

Post by atomidude » Sat Jul 23, 2005 5:49 pm

i just underclocked my Gigabyte fanless 6800 down to 200MHz from stock 325MHz for 2D only. by doing that the idle temperature dropped 16C. would this damage it? just concerned that when i start a 3D application the frequency goes back to 325MHz instantly...
anyway, would be nice to use the card this way. firefox doesn't really need the full power of a 6800 :)
any thoughts guys?

geforce1
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Post by geforce1 » Sat Jul 23, 2005 6:54 pm

It won't cause any harm to underclock your 6800 for 2D mode. Maybe if you clock far too low artifacts may appear (which may be core:mem sync related), but otherwise, it's fine. Just because a chip is rated at a certain speed doesn't mean it can't run slower if desired.

atomidude
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Post by atomidude » Sat Jul 23, 2005 8:27 pm

thanks for your reply gforce1!
still testing, for over two hours now my gpu runs at 200MHz. no sign of artefacts, it seems to run whitout issues so far. temperature idle is an amazing 32C now, down from 48-50C!
i would not underclock the vga ram, there's not much use in it since they don't generate too much heat. plus i'm afraid doing so would get the videocard unstable.

peterson
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Post by peterson » Sun Jul 24, 2005 12:56 am

How stupid of me not to think of this. I'll test it right away! Thanks for the tip! :D Hope it works.

Lawrence Lee
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Post by Lawrence Lee » Sun Jul 24, 2005 1:30 am

I recommend everyone underclock their card in 2D mode. Especially if you have a decent card in a non-gaming system. Underclock it, unplug the fan, embrace the silence.

peterson
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Post by peterson » Sun Jul 24, 2005 1:58 am

For some reason my T-Balancer report no change in temp, but the nVidia reports only 27°C in temp. Strange since the sensor sits on the VF700 heatsink.

atomidude
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Post by atomidude » Sun Jul 24, 2005 3:31 am

peterson, it takes some time for the temperature of a heavy heatsink to get down, there's some thermal inertia... the chip cools down much faster, it weights only a few mg :D

i love it, the only reason i had to keep my Aerocool Turbine at 800 rpm was the vga. just hate to see it idle above 50C. now my fan is at 680 rpm, ambient 18C (winter here) and my idle temperatures are the following:
CPU 29C (A64 3000+ with c&q active, crystal cpuid at 1.0V, 1GHz)
VGA 32C (Gigabyte 6800 with passive cooling, using coolbits to underclock in 2D mode to 200MHz from 325 MHz stock)
HDD 33C (Samsung SP1614C inside a SilenX Luxurae enclosure)
Case: 26C (Gigabyte K8VNXP with passive hsf since i removed the noisy little fan)
All of the above cooled by the Aerocool Turbine, no other fan inside my case since the CPU has a TT103 fanless on top and the Antec Phantom has no fans either, as we all know, hehe

noise? what's that? :)

peterson
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Post by peterson » Sun Jul 24, 2005 5:52 am

Yes, but now it's been undervolted for more than 2 hours, and no sign of changes in the T-Balancer.

atomidude
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Post by atomidude » Sun Jul 24, 2005 6:46 am

peterson wrote:Yes, but now it's been undervolted for more than 2 hours, and no sign of changes in the T-Balancer.
well, that's strange... are you sure the gpu is underclocked? make sure you underclock the 2D mode only, otherwise there's no effect at idle... if it is slowed down, at what frequency is it running now?

peterson
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Post by peterson » Sun Jul 24, 2005 7:29 am

The strange thing is that forceware reports only 26°C now. It's underclocked to 200MHz. Memory on default speed. I havent opened the case to feel with my fingers yet. Maybe later.

JazzJackRabbit
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Post by JazzJackRabbit » Wed Jul 27, 2005 8:24 am

Try to install some real-time monitoring programs like rivatuner so that you can watch both the temperature and the frequency. I have also found that certain applications like playing mpeg4 videos will cause the card to switch to 3D mode at full 400Mhz (I overcloked my card for 3d mode). Actually just keeping ZoomPlayer open will cause the card to switch to 3D mode, only after it's been closed the videocard will drop the frequency.

atomidude
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Post by atomidude » Wed Jul 27, 2005 1:11 pm

you are right Jazz, video applications do bump the frequency back to stock. i use a hdtv card, if the software is on, even minimised, the temperature goes back to stock speed values. not that's an issue, but it is nice to know :)

peterson
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Post by peterson » Wed Jul 27, 2005 10:45 pm

I've tried both WinFox (LeadTek's SW) and Riva. Both reports it's ok and the new setting is 200MHz. But now no temps are lowered. I give up. I need that adrenaline for other stuff. :)

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