5970 /5870 Tri-fire artifacting

[Jacky60]

I have added a XFX 5870 to my Sapphire 5970 and I'm getting blistering frame rates-can't stop smiling except if I try and overclock both to 900 mhz with afterburner I get artifacts in Arma 2 ( Not a popular game with anands readers I fear).

At 850 mhz they're pretty much ok but the extra 50mhz speed bump (at same 1.162V) means artifacts almost immediately in Arma 2 benchmark and MSI kombustor artifacted and crashed at 72c (hottest GPU).

Fans are at 100% above 40C and artifacts take a while to arrive but I'm pretty sure its cooling related because when I added additional fans it was mitigated somewhat. Extra voltage makes artifacting happen sooner but GPU temps above 64C create artifacts very quick. I know VRM's are the critical component but can't understand how VRM's get 40c hotter than the GPU's-any ideas or solutions other than water (excuse the pun).

 

[AdamK47]

Doesn't the 5970 have a default clock speed in the 700ish range. Getting 900MHz from it sounds a bit too much.

 

[digitaldurandal]

The solution is simple. Stop overclocking. The 5970 chips may not be able to handle the overclock, they default slightly lower than the 5870 chip. With trifire you should be fine at default clocks, I doubt that the extra 7% clock speed is going to amount to much in terms of time spent over 60 fps.

Ask yourself, is it really worth it to OC in your situation?

Even in my situation I have my 5870 @ 900mhz (+50), but it doesn't make a large impact on framerate at 5870x1200 anyways perhaps 1 to 1.5 fps min difference in BFBC2 which shows the most improvement, so I stopped upping the clocks.

 

[MarcVenice]

My 5970 won't do 900MHz, let alone when cf-ed with a HD 5870 ...

And with that much power, why do you need an OC that badly?

 

[Jacky60]

Re:Stop overclocking: I guess you're right I've throttled back to 850/1200 for both cards and it maxes everything pretty much I just like to push the envelope a bit.

I'll 'Step away from the cards Sir'

It was curiosity as much as anything to see how fast they'd go.
PS the 5970 was good for 920 alone without 5870.

Thnx

Thanks for the feedback

 

[scooterlibby]

I had thought about tri-fire in the future and figured I might have to sacrifice my 900mhz OC on the 5970. I'd still take the tri-fire over the nice dual GPU OC.

Just curious OP, have you done any benchmarking and looked at minimum frame rates? I remember somebody here posting with a 5970+5870 setup that got phenomenal average frame rates but atrocious, game impacting downward spikes.

 

[Dark Shroud]

You're over complicating this. Just OC the 5970 to the same speed as the 5870 and call it a day.

 

[Jacky60]

With regard to minimum framerates they stay very high and I've seen few and not significant downward spikes-like dropping from 140-160 to 100 or from 60/70 fps to 40-50. I'd notice them as Arma 2 is incredibly demanding and they do sometimes drop to 35-40 fps but generally it holds 55-60fps consistently (max refresh rate 60hz ans can't be bothered to fk around diusabling vertical synch in Arma 2) Arma 2 settings all highest possible apart from post processing disabled and video memory=default.

BF2BC with all setting maxed (1920x1200) It rarely drops below 120fps and Unigine Heaven 2 benchmarks comes in at 80.9 fps, (16xAF, 4 x AA) min 26.2 max 189 with 16xAF 8 xAA the score with Heaven 2 is 53.6 minimum 9.5 max 159 -If Heaven was a game the slow downs especially at 8 x AA would be really noticeable but fortunately its not and I think its due to tesselation more than anything. Settings are high shaders normal tessellation 1920 x 1200 At 850mhz all cores 1200mhz all memory