Visiontek 3850 Overclock Issue

bastion

Senior member
Mar 13, 2002
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I'm experiencing an OC issue with my 512MB Visiontek HD3850. I just built this system over the weekend. E2200 (OCed to 3.0), Gigabyte P35-DS3L, 2GB Corsair DDR2 800, all in an Antec P180 with a 500W Antec Earthwatts PS.

When I got into CCC (running Catalyst 8.1 drivers), it appears to only allow me to OC the GPU clock 20MHz, and the Memory Clock 75Mhz. It's like the range is locked in. I know that this is a factoy overclocked card (the pic shows the stock settings), but that still seems weird. Why is it giving me such a small range? Do I need to flash my bios, or do I just need to stop using CCC and use ATT instead?

CCC Screen Shot NO OC

Here's what happens when I use the auto tune. I ramps the GPU up a couple times to 720, then steps it down to 710, then does the same thing to the Memory, taking it up to 950 before settling at 940. And then after applying them, I still show my current clock settings being 700 and 875. WTF? :confused:

CCC After Auto Tune
 

Blacklash

Member
Feb 22, 2007
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My guess is you have a revision 2 BIOS. My MSI card came with one and I was limited to 730|1010. I flashed in a rev1 Powercolor BIOS now I can select up to 770|1117. My cards don't do over 760|2038 and that's better than being held to 730.

You can find BIOS over @ MVK Tech-

http://www.mvktech.net/compone...nc,selectfolder/cat,1/

You could also OC with ATi Tool or RivaTuner and skip Overdrive. I use RivaTuner to jack up my fan to 55% when I game.

If you've never flashed a card and don't know much about it, skip it and just OC from ATi Tool or RivaTuner. Make sure you get a 512Mb BIOS if that is how much your card has on board.

Use something like the test in ATi Tool to see if your clocks are stable.

People using Vista x64 should download the signed drivers below for Rivatuner. That way you can skip doing F8 every darn post to defeat driver check.

http://www.techpowerup.com/dow...64_signed_Drivers.html
 

bastion

Senior member
Mar 13, 2002
231
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I've had some experience with NVIDIA cards (Rivatuner is great with them) but this is my first ATI. From what I've read I thought you could use Rivatuner for everything except OCing on ATi cards, but I guess I'm wrong.

I'll play around with Rivatuner and ATi Tool a bit before I flash the bios, but you are probably right. According to the CCC, the bios version is 010.073.000.001

Still don't understand though why even after simply using the Overdrive Auto tune, it doesn't appear that the OCed settings are actually being used.
 

bastion

Senior member
Mar 13, 2002
231
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ok, after reading some more info, it looks like those upper limits are teh actual set limits for the card, so it appears that a bios change is the only way to unlock a higher clock setting. I mean, I know it's factory overclocked, but only 20MHz on the GPU? Give me a break!
 

Spikesoldier

Diamond Member
Oct 15, 2001
6,766
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the problem with using a utility to set clock frequencies is that you lose the function of powerplay if you are energy conscious.
 

Killrose

Diamond Member
Oct 26, 1999
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I have a Saphire 512mb card and I set my clocks to 720/950, hit the "Test Custom Clocks" button and when it finished hit the "Accept" button and before leaving I hit apply. Funny thing is when I check the clock freq with GPU-z it says 715/945.

Oh well.
 

bastion

Senior member
Mar 13, 2002
231
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Ok, looks like it's just a weird issue with CCC. Not sure why though. Maybe its an issue with the 8.1 Cat drivers? Anyway I disabled it from the tray tools, and then loaded Rivatuner. RT took to it with no issues. Let it analyze the frequencies with a reboot, and then I was off. Ended up with a stable OC at 790/1000.