sri_lion said:
Well...... probably in SL its not a good idea ( i would'nt have bought it either) to buy 2 for 40k because its DAMN expensive! But sooner or later you're gonna have to upgrade your VGA so why not get a "CROSSFIRE" version?? When its costs almost same!!
Yes you need motherboards with 2 PCI-E slots that's agreed!!! But DUAL CARDS COMBINED DOES'NT DELIVER the goods?????
No..... STRONGLY DISAGREE!! I've seen it... I've played on it!!! Its as smooth as silk!!!
Becuase when redering the frames the cards take turns (for example odd and even frames will be taken over by different cards) so it makes it more fatser!!!!!!

and there are many other redering modes!!!!!
Only issue here is as you said the motherboard but.... PCIe slots already a regulation thing in motherboards!!!!
Crossfire delivers. But not always. There are few games which are not yet supported. In fact, they perform slower than the exact single card setups. If you have bought X1900 series card, sure crossfire is very important because you wouldn't want to throw that Rs.50,000 card away when you buy a new one. But for X1600 cards, I think you should collect some more money or wait a little and buy a 7600GT card.
Anyway, my point it, why buy two X1600 cards if they TOGETHER perform slower than an X800XT? Well, you have to unlock your X800GTO card and overclock to reach that performance. But still, it's only Rs.9,500 and two X1600 cards will be US$250 even in USA (for both cards). The only, I repeat, "the only" advantage X1600 cards have over X800 series is pixel shader 3 support. But the X1600's performance is so low that PS3 support will make things worse.
X1650XT's story is different though. It's a fast card, which is on par with 7600GT. But not the best card for a HTPC because it uses a lot more power.
If you really wanna compare the video cards, here's a good place to look.
http://www23.tomshardware.com/graphics.html?modelx=33&model1=556&model2=568&chart=199
Clearly, X800GTO is no match for a 7600GT, until you unlock those 4 pipelines and overclock to X800XT speeds. Then, in some case, X800GTO is faster than 7600GTs in SLI (when you use very high AA and AF levels).
Edit:
When you compare results at tomshardware, don't check the lowest settings. Check for the most demanding settings, such as 1600x1200 4X AA and 8X AF. X1600 cards are pathetic.
Edit:
Unbelievable how X800XT is as fast as a 7800GT.
http://www23.tomshardware.com/graphics.html?modelx=33&model1=556&model2=568&chart=211
And I have to agree that nVidia cards are simply untouchable in OpenGL games.

It's a driver issue. ATI still haven't been able to get it to work.