smoothcig

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I have a Sapphire 4830 and I have BIOS flashed it to my stable clocks of 741 on the core and 1080 on the memory. Today I decided to venture into waters unknown and do a pencil voltage mod. Everything went as planned and now instead of 1.15 volts on the core I have 1.28 :D BUT the problem I'm having is that every time I go into Rivatuner 2.24 and increase the core clock just a teensy little bit (from 741 to 743) Furmark crashes after about a minute or so. I even did the unthinkable and underclocked it a little bit and it still crashes! BUT when I set everything back to normal (741 on the core, 1080 on the memory) it runs Furmark just fine for hours and hours. I have tried an older version of CCC, 8.12 which I think is what I had when I first bought this card, and it still crashes at even the slightest change of clocks, NOT using the Overdrive feature of course. However I clocked it to 769 on the core and ran the ATi Tray tools artifact scanner and it was stable for 20 minutes with temps topping out at 72C so I thought to myself "hey it's stable!" but after a half hour of Fallout 3 it crashed :'(
So, what do you think could be the problem?
 

smoothcig

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Well, it turns out my memory clock was unstable. I took it down to 1000 and now I'm up to 792 on the core with voltage at 1.28 idle and 1.32 under load. It took a bit of work with a No. 2 pencil to get it above 1.20 though. Hopefully I can buy a No. 3 pencil today or tomorrow. Wish me luck!
 

smoothcig

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I don't know if anybody is following this but....
I just happened to find a 2B pencil in an art box or whatever and erased my old 2 HB marks and applied the 2 B. Now my core readings are 1.37 idle and 1.40-1.41 on full load. Temps are a little high but I have it stable on 842 on the core! That is a 100 MHz increase and I'm still going :D ! If you are skeptical of my overclocking prowess I can send you a pic of furmark running because, alas, I don't have an imageshack or tinypic account and it's about 2:00 AM here and I'm ready to go to bed.
 

smoothcig

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YES! I had some old copper laying around and I cut off two thin pieces folded them in half with some pliers and put them on my RAM (which does not have any heatsink on them at all Oo) and it didn't drop my temps by much, maybe 4 or 5 degrees Centigrade on the memory, but it let me overclock it all the way up to 1160. According to ati tray tools that was stable but Furmark gave me a different answer. As in, artifacts all over lol SO I took it down to 1097 and Furmark agreed that it was stable...
I decided that my temps were getting to the unreasonable point of 83 on the core after 15 minutes of furmark and about 75 when playing Crysis for 30 minutes so I will not be buying a 4 B pencil like I had planned to get the core voltage up to 1.45 LOL (I just might do it if somebody dares me to ;) )
My final stable clocks are 842 on the core and 1097 on the memory. Here's the link to my validation, http://www.techpowerup.com/gpuz/kgbqh/
I might post back with some 3dmark06, Vantage, Crysis benchmarks, or whatever but for now have a good night!

 

Iarwain

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Sounds like great fun man.

That 842 on the core is 8 mhz away from 4890 stock clocks, I'd like to point that out.

It does have fewer SPs and obviously lower memory bandwidth, but that's still an awesome clock.
 

smoothcig

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hmmmm very interesting stuff. I have my memory at 1125 and a couple games are completely stable, that I've tested so far, (Fallout 3 and Call of Cthulhu: DCoTE which is one of the best games I've ever played btw) but Furmark locks up after 3 minutes once temps get to 84 on the memory... The memory and core are about the same temperature not matter what I do... I think either ATi or Windows 7 is restarting my graphics driver because the temps get to high. If I run the Crysis benchmark my temps SPIKE from 50 Centigrade idle to 75 in a matter of seconds and then it crashes and Windows says my "ATi Radeon family graphics driver stopped responding and had to be restarted". However, the actual Crysis game can play for hours with temps getting as high as 88! 3dMark06 can loop 3 times (that's all I tried) with temps only getting to about 72 on the core and memory. Sadly my score is only 12,404 probably because of my lame e5200 (getting an e8400 in a matter of weeks :D). Furmark seems to be the only thing that fails apparently because of temps.
Can anybody recommend a GREAT (not just good) aftermarket cooler for a 4830? I wanna pump 1.48-1.49 into this baby and see what she can really do!
 

tijmen007

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Wait ? 1000 Mhz on DDR3 memory with no cooling, and it did not blew up already ? wow...
Nice overclock of yours though , nice work!

Tijmen
 

Iarwain

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For a cooler, if you're okay dumping heat in the case, then ZF-1000 or Scythe Musashi. I have a Sycthe, I love the thing. As completely silent as an air cooler can get.

Lower the memory OC a bit, and see if the temps go down first. Overclocking the memory can really heat up the MemIO sensor, which isn't actually the memory chips, it's on the die.
 

smoothcig

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I just ordered it! Very excited to see what my $99 dollar card can do when it comes on the 6th :) What do you think I should cap the max voltage at? I was doing some digging on other forums and I saw that someone keeps their 3850 at 1.6 Volts 24/7 :ouch: Hmmmm. More reading makes me think that I should cap it when the temps start to get really high... With the memory at stock though my temps on the Core are 72 Centigrade tops in games and 77 in furmark after half an hour when they are completely stabilized. 114 is what ATi says they are rated for, but since I'm overclocking I think I should keep it below 70 or 75.
So my questions are what should I cap the voltage at and what temp do you think I should stay under? I'm idling at 45 and full load 77 with stock cooler.