Radeon 4870 OCing

[z999]

Hi,
I have a new computer and got to the stage of OCing my video card, I'm using RivaTuner and I have a couple of questions:
1) How do I separate the core clock and the shader clock?
2) Does the temperature affect the appearance of the yellow things (forgot their name...)?
3) I'm stuck on 825 core and 1080 memory, I've seen people get MUCH better OCs w/ the stock cooler (and the fan mod), how can I get better results?
thx,
Ziv

 

[assasin32]

Yeah im a noob at this catorgory as well (just OC my 8800gts G80 card thursday night, still am not an expert at OC'ing GPU's), but you can unlink the core and shader clock by clicking on the link button which will take away the checkmark and obviously mean its not linked. And as for temps it may have a little bit of affect on the appearance of artifacts (those yellow things), but thats may be due to the card overheating (I think may cause it, either way lets just say letting your card get pretty high up there in the temp range is not good either way)

Just don't forget to set the fan speed higher in rivituner while OC'ing, it can only help to keep it cool.

 

[z999]

I can't find the button... I'm posting a screenshot and tell me where I'm wrong:
[img=http://img517.imageshack.us/img517/6198/screenjd7.jpg]
By zivpeleg
thx

 

[eklipz330]

post your picture in photobucket, your img doesnt feel liek working

i dont think you can unlink the core and shader with ati cards

what rivatuner version you have? 2.11 supports CAT 8.8

new CAT 8.10 apparently has fan control in the Overdrive section[if you cant manage to speed it up through rivatuner]

i would keep the Hardware Monitoring up while i run ATITool artifact check, it works great IMO... I run it for about 45mins, and if I don't see artifacts, I usually consider it a safe overclock... but the timer also has to his 45mins, cause if it doesn't that means something popped up while you weren't looking

Furmark is also pretty good, but it won't tell you when artifacts pop up, which means you gotta look at it for 45 mins -_-

 

[calam1ty]

It's only with Nvidia cards where you're able to unlink the core clocks and the shader clocks form what I'm aware of. I had an 8800 GT before and a 4870 now. When overclocking my 8800GT there was the option to unlink but with the 4870 there's none. I think the reason is that AMD decided to have their shaders clock the same as the core so that they can have more shaders while nvidia seperated them so that they can get better shader proformance with fewer shaders (240 max shaders on a 280 GTX vs. 800 on any 4800 card).

 

[Dopekitten]

Yea you cannot unlink shaders and core clocks on ati cards.

Also, now that catalyst 8.10 is out, download that because you can change fan speed there.

Next, download a modded bios, like this one:
http://www.mvktech.net/index.php?option=com_remository&func=fileinfo&filecatid=2747

So that you can up your core clock to 900 max and i belive 1200 max mem clock.

Then just test and see how high you can get. Note that the memory's actual spec is only 4000mhz (1000mhz x4) thats what it's supposed to run at, so above that, you should run into stability issues. For me, i run at 830/1000 for normal uses, anything above that causes stability issues. However, i can run at like 870 core and 950 memory with problems, it's just that i don't feel i need that, and im not sure what docking the memory 50mhz does on performance

If you're really gung-ho about overclocking your card, you could try volt-modding it so the core/memory gets more voltage e.g. higher overclocks. There are plenty of threads about it, just search "4870 volt mod" on google.

As for "yellow things" wtf are those? artifacts?

 

[z999]

kk, thx every1. I'll keep those values. yeah I meant artifacts. it was like 2 AM here when I posted it so my brain wasn't fully functioning.

 

[enewmen]

I'm also looking on overclocking the 4870.
I already got Ati Overdrive working well enough. But that is limited to 790 MHz GPU.
How can I clock beyond 790 MHz? Save the new clock in the card so I don't need to keep reloading RivaTuner every time for example.

I think clocking to 850 is small enough so I don't need to install a MODDED BIOS. Perhaps the modded bios is safe enough so I never need to think about it again?

Thanks!