Overclocking a HD3870

wirelessfender

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Mar 19, 2007
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I feel very lucky right now as I was the last person to get a Sapphire Radeon HD3870 from newegg before they went out of stock and up $50 :bounce:
It will get here thrusday, but I would like to ask if anyone has found any reviews that include overclocking the 3870. I would like to overclock it but I need to know if its worthwhile.

Thanks :)
 
I'll tell you my experience overclocking the 3870. 3870@stock speeds using e6400@2.9, 2gb ram on a MSI P965 Platinum motherboard. I scored 10,500 in 3dmark06. I bumped the speeds up to 825/1220 and scored 11,022. After that, I bumped the speed to 850/1275 and scored 11,055. I probably won't try to push anything further as I am happy with that score. I feel as I am CPU limited anyway.
 
Here is a 3870OC benchmark that shows how your performance might scale:
From DriverHeaven review which also covers CrossFire support)

gow.jpg

 



Have you had any lockups yet ? Just curious .... want to try overclocking mine but since they're so darn hard to get don't want to fry it . :sol:
 


I have not experienced any lock ups. Right now I have my clock set at 840/1291. No problems anywhere including gaming and benchmarking. If I were you, the furthest I would go would be an 850 core. It will lock up at anything past 862 core speed anyway unless you flash your bios (not worth it).
 
Yep .... found that out .... opened her wide open and vista turned black . Am safely running 777/1387 ..... no problems yet .... seems memory speed up is alot more stable higher than running up the gpu too high .
 


You think your CPU limited. I have a Pentium 4 3.0G 630, 2G pc-5400 running a 3870.

I am taking baby steps with OCing my Sapphire 3870, i am at 805 core and 1200 mem. I tried it at 825 and it blacked out after a few minutes. At 825 core, it was close to 85 degrees c at load. At 800, i am at 75c at load.

With 2xAA, 2AS and most of the eye candy, i am getting 60+FPS. for COD4. Usually higher. Until i upgrade my mobo and CPU, higher settings really drop my performance.

EDIT: i had my CCC controlling all the settings, set to quality. i was getting real low FPS. When i set it all to app controlled and let the game handle it, it ran a hell of a lot better.
 
Well I'm running a core2duo .... 3 megs .... 3870 ... and had almost the same results on the blacking out . So don't think any upgrade of a cpu will work . Not only that with the ccc and vista at performance I got crap all over my screen in battlefield 2142 . Did'nt even try crysis with those settings . But turning off almost all the effects in vista did help ... and eliminating the non essential loading of components did improve it all a bit . Check this link http://redchaos.wordpress.com/2007/03/06/tweak-vista-for-gaming/

And this one http://www.tweakguides.com/Crysis_2.html
 
yeah, when i set CCC to permormance my FPS dropped to 20-40. What i did was use custom settings and set all the 3d settings to "application controlled". I started getting 50-70FPS with COD4 on medium settings, 2xAA, 2xAS at 1024x768. That is about where it should be. In Tom's article "AMD Radeon HD 3800: ATI Strikes Back" http://www.tomshardware.com/2007/11/15/amd_radeon_hd_3800/page17.html the 3870 on COD4 was getting slightly lower at higher res.

anything i try over 800/1200 locks up.

Another thing: i had COD4 playing at some custom settings getting 50-70FPS. I reset COD4 to optimal settings. Now i am getting 70-90 FPS. 4xAA, 4xAS, 1024x768.

Bottom line: CCC 3d settings to application controlled, ATI Overdrive 800/1200, I am happy now. If i get a new cpu and VGA cooler i might try more later. one thing i forgot to mention, my board is PCIe x16 not 2.0.
 
I am kind of shocked to see all of the lock ups at such a low overclock. Has anyone tried the new drivers to see if they added anymore stability? Also, what company is the marker of your cards? I have a Sapphire card.
 


Gigabyte sell a 3850 with this cooler already on and in the couple of reviews I have seen nobody has had load temps as low as that. Have you had riva tuner or Ati tool logging those temps or have you just come out of a 3d application and then checked them? If possible post some screen shots. I'm not calling you a liar or anything I'm just a bit pessimistic about those values. I'm looking to buy a 3870 in the future so I would be interested to find out.

Edit: Could you also post a screenshot of GPUZ because that is one hell of an overclock.
 
Sorry for the typo guys load temps are 55 not 44 sorry....BTW its only 55 and under at night, on a warm day temp get around 60....the O/C has been achieved with the 7.12 Driver not 7.11.CPU-Z show that im a little under 880/1246

P51.jpg
 
Set my sapphy 3870 to 815/1200 without even breaking a sweat.

ONLY THING YOU SHOULD KNOW is DL riva tuner or something of the sort to alter the default fan speeds (if you use stock cooler). I manually set mine to run at 75-80% during games and it keeps things in the 30's @idle-60 degree under 100% load

run it with a e6320 @2.9, 2gb ram @830mhz, x38 chipset=
10,805 3dmk06
 
Cheers detpower

That is a good overclock considering its not meant to be able to go over 860 without the bios update. Those temps are very impressive. They are much closer to what I was expecting. I just thought only a 9c increase under load was asking a bit much. When I do get a 3870 you have given me a target to aim for.
 




I can overclock my gigabyte HD3870 up to 960 core clock and 1110(2220) memory clock from stock 825 core clock and 900(1800) memory clock. and my card idles at 32 degrees with my stock cooler

http://pan.fotovista.com/dev/9/5/00163659/l_00163659.jpg