Sapphire 4870 oc issue

error8

Diamond Member
Nov 28, 2007
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Ok, so I guess that my computer started hating me. First my cpu doesn't like being stable at 4 ghz and now the card doesn't like oc'ing anymore.

I have my Sapphire 4870 since September, if I remember correctly. After I messed with the fan, I overclocked it. It was perfectly stable at 830 mhz since day one. Passed hours and hours of ATI artifact test, Crysis and played other games with no problems. The ram, on the other hand, was a tough nut to crack. I first thought it was stable at 3,9 ghz, but it wasn't. Worked fine for almost 3 weeks at 3,8 ghz, but a gray screen in BIA changed my opinion. Then I went another 100 mhz lower and now ATI tool gives me artifacts at 3,7 ghz. What the hell??

The core also became unstable at 830 mhz with ATI tool. I backed it to 815 mhz and seems to work fine. But why?? My card never went over 60 C under load ( fan at 50% ) and the mem stayed around 65 C. I just don't understand why did the memory became unoverclockable. And why the hell did I loose those 15mhz on the core? Has anyone encountered something similar to this?
 

Hauk

Platinum Member
Nov 22, 2001
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Pretty high oc, 800+ seems rare. Think you may have been lucky till this point? No logical explanaiton, other than 790 core at any fan speed is damn good for these cards...
 

error8

Diamond Member
Nov 28, 2007
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It never happened this to me. I overclocked all my videocards and usually, you might have an unstable oc from the beginning and you just don't know about it, until you run into a very demanding game. But this card played and finished Crysis Warhead and it was rock solid in ATI tool, when all of a sudden it became unstable at those clocks. I just don't get it. There was no temperature increase, nothing that can interfere with my oc...
 

mpilchfamily

Diamond Member
Jun 11, 2007
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Considering your having issues with both the CPU and GPU OCs then it may be a power issue. Could be the power from the PSU isn't as clean as it was before. Working a PSU hard like that will wear it down a bit and cause it to supply less power then it could before and that power could be a bit more unstable then it was before. I don't think iis cause to buy a new PSU. I don't think the unit is going bad just sowing some age is all.

It could also be the chips themselfs showing some age from being over worked.
 

error8

Diamond Member
Nov 28, 2007
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Since my PSU is only 5 months old, I really doubt it could start showing its age, since my system, overclocked as it was, hovered around 400 W or so ( according to PSU calculator) . But who knows, maybe you are right, or maybe the chips are showing their age, since any other logical explanation doesn't exist.