Graphics Crossfire/SLi Questions

As some of you may know I have posted a couple times concerning my disappointment with my XFX 7600GS XT.
Overclocking
Other problems
My motherboard supports Crossfire, so I think the next cards I buy will be Ati's. I don't know much about Ati's, though, so I have a couple of questions:
1. What's the lowest possible price I could pay for two Ati Crossfire cards? (I have a SEVERELY limited budget here).
2. Do I need a Crossfire-rated PS in the same way as SLi?

Two more questions - nVidia related:
3. What is nVidia's "multi-GPU" configuration that I've read in the newest driver documentation and how is it different from SLi?
4. Also, the driver's .chm said that if I saw an option for SLi in the Control Panel that my motherboard supports it. Well, I am seeing that option in my Control Panel, even though my mobo (ASUS P5WD2-E) technically doesn't support it.

Thanks a lot!
Sam

 

1.it depends, i saw X1800GTO's for £116 on lowestontheweb bout 2 or so months ago, but tbh most places dont have stock of x1800 cards anymore due to the x1900seires reshuffle. tho u can use corssfire with lowerend cards like the x1600's and others.
2.not allways but it does help with any trouble shooting problems if you get them.

3. is simply Sli or Quad sli. thats what their talking about.
4. No the graphics card suppords sli, not the mobo, the card has the option to be paired up.

TBH ur just better off with a more powerfull card, weather Ati or Nvidia dont matter 7600Gs aint exactly the fastest card in the midrange, for round £160 u get a 1900Xt and that should blow the pants off the 7600gs you have.

corssfire and sli are only really nessasary if you play at uber high rez and game heavely. personnally i dont see the point to it but it has its place.

 

i have a saphire x1800xt 256 mb and it runs everything i throw at it, even before i oc'ed it. hl2, css, w/e...like atanum said, you'll be better off getting one $200 card than 2 $125 cards...the power consumption and heat generated by two cards just makes it not worth it...again, unless u are gaming all the time at super high res...which I think is very overrated...