If you have a bad AMD/ATI card...

That provide errors/invalids results

You can try to reduce gpu/mhz and memory/mhz in amd overdrive section of amd catalyst center

I have a card like this

VTX3D HD7970 3GB GDDR5 X-EDITION - ( VX7970 3GBD5-2DHX )
GPU= 1050 MHz MEMORY = 1425 MHz (original settings)

I have slowed the card down to 800 MHz for GPU and 1000 MHz for MEMORY

and the errors/invalids have decreased

so my conclusion is that the work units provided by milkyway are goods
and my card, don't support original frequencies, that the product vendor tell it was for

I have done more tests

If u have a 7950 and have too much errors

Try 850 MHz for GPU and 1250 MHz for Memory

It's AMD default
http://www.amd.com/fr/products/desktop/graphics/7000/7950/Pages/radeon-7950.aspx#3

If u have a 7970 and have too much errors

Try 925 MHz for GPU and 1375 MHz for memory

It's AMD default
http://www.amd.com/fr/products/desktop/graphics/7000/7970/Pages/radeon-7970.aspx#3

There is no need for Milky Way to run with memory speed so high, it only leads to higher temperatures. I run the memory on my HD5870 card at 300MHz. It works well and stays cooler.

Thank you, swiftmallard* for your advice

But, i speak for 7950 and 7970 not for 5870

300 Mhz look like very slow for your card and my cards

The official memory speed for a 5870 is 1200 MHz
http://en.wikipedia.org/wiki/Evergreen_%28GPU_family%29

PS: 7950 and 7970 can not go under 800 MHz for memory

PS: 7950 and 7970 can not go under 800 MHz for memory

I am pretty sure his point was that here at MW faster memory doesn't help, so crank it down as low as you can and see if it works that way. It doesn't matter what card you have, faster memory speeds doesn't help here. You said you set yours at 850 and 1250 but it can go as low as 800, try lower and see if your card responds like the 5870 did, if not crank it up a little bit at a time until you are happy with the results.

You could also look at tuning down the frequency that Milkyway@home runs chunks of its simulation and checking to see if your cards are dust free... I mean really dust free.

My card was spitting errors and between the dusting out of the cards (twice) so they could cool properly again and moving the value to 80 in the preferences all is well now with my 5970 crossfire setup it appears to slice through the work units once again and is stable.