Various 2900XT Crossfire problems, need help from HW gurus! (PC shutdown, flickering)

[spajdr]

Hello guys, this will be long thread, at least from me.
So where to start, i got two Sapphire 2900XT cards in Crossfire. Didnt seen anyone got any problems, well i got few and ugly ones(again .. got different somewhat problems with 1900XT CF year ago).
When i install drivers from CD, Crossfire working fine, BUT speed is not so good as from 7.5 (or later non-public one). For comparison, i run pixel shader test from 3D Mark 06, with CD driver i got 550fps .. with 7.5 i got 675fps.
And now the problem, when i install 7.5 and got higher speed in every game, my screen flickers, i tried to capture it by fraps, but its not visible, its horizontal lines, quickly moving up and down, in multitexturing they are more lines (like 4mm line per 10cm, moving up or down). It also have some somewhat seen red color when flickering. Thats not all what bugs me (i will not talk about CCC problems i got). I tried these CATs under XP and also VISTA, its no difference.
Another problem, when i overclock cpu to 3Ghz, in like 5 minutes computer shutdown then goes up and for like two seconds all leds flickers then its ok. I could understand that Fortron 700W cant handle all of this (8 fans in case) but i got second one 300W X3 Booster which can handle alone two 1900XT in CF, if i dont overclock cpu computer dont shutdown.
So im asking you guys, what you would try? Would new PSU fix all these flickering i see and also shutdowns when OCing CPU.
Im just not sure what to do now? dont wanna throw another money into some badass PSU to find it didnt help me (i also exchanged one sapphire card, but nothing changed).
If anyone got any idea what to do, tell me please, im really desperate.:shrug:

[jimmyz]

i would try a different psu, while that one may have sufficient rating to get crossfire approval. it doesn't mean it isn't the problem.

[ColonelCain]

I would go for a new PSU as well. I think that your best bet is a PCP&C 750w. Here's a cheap one: PC POWER & COOLING Silencer 750 Quad (Copper) S75Q Power Supply Retail ***Free Shipping*** $172.50 (http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=10005613)

[spajdr]

Would like to get something tomorrow :)
I thinking about Thermaltake 850W Toughpower
or
Fortron Epsilon 800W (its 4x20A compared to 4x15A on my 700W).
I just cant find any shop with 1000W PSU on stock in my country :)

[cadaveca]

DOn't bother with the FSP unit ;)

[spajdr]

Ok :)
What about that TT? it have 18 18 30 30A on 12V rails.

[NickS]

The TT is a good unit, go for it! :up:

[spajdr]

Thanks guys, will have TT 850W today :)

[elmor]

About the flickering, what setting for Catalyst AI? There are some notes in CCC about Catalyst AI resulting in flickering when running CF.

[spajdr]

Tried standard or advanced, but no difference.
Only difference it was that with CD drivers it dont flicker, but speed was 15-20 percent lower, while with CAT 7.5 and leaked newer ones speed increases but it flicker.

[Idaho]

Please let us know if the PSU solves the problem, should be interesting

[spajdr]

Yeah, PSU solved the fooking flickering :)

[cadaveca]

;) I knew it would fix it.

[spajdr]

actually new PSU just fixes shutdown, problem with flickering was Avivo color correction, if i increased or decrease hue or saturation, then it started to flicker, also crossfire is slower if i dont disable and enabled it thru CCC, even with hotfix.

[cadaveca]

Hmmm, interesting. R580/480 Crossfire is a victim of flicker with an adequate PSU.

However, I had one bit of flicker in '06 Canyon. 7.6 fixed it. But that little tidbit about colour is very interesting.