Crossfire X1900 with newer ATI card?

Currently my system has a two-year old X1900 series Radeon. It's x16 (so is the PCI-E bus) and 512MB. I bought it with the system, two summers ago. I'm thinking of upgrading to a newer fancier card. I've had good luck with ATI so far, so I've been eye-balling some of those: in particular, the 4850.

Here are my questions:
- Is it possible to Crossfire my old X1900 to a newer card (such as the 4850)?
- Is there an advantage to this?

I understand unless I'm buying two top end cards, it's not worth it to buy two cards and Crossfire/SLI them together. But if I already have the card, I figure why leave it to collect dust? I suppose I could at least support four monitors (Matrix Screensaver ftw) but I think it'd be neat to up my 3D potential, even if only a little bit. If it would work, I'd be willing to survive with one monitor on my gaming system.

I can't find the docs to my machine, and I have yet to confirm whether my X1900 is Crossfire-Edition or not. I've tried the Catalyst Center and Everest (from Lavalys). Neither has any mention of Crossfire on my system, but I see no entries that say something like "Crossfire: Not supported", so I can't confirm either way. Is there a way to determine this without the paper docs?

Thanks a lot for your time.

Exactly, and really if you're selling the X1900, take the proceeds and try to get yourself into an HD4870, although it may be worth waiting for a 1GB model.

Unfortunately can you not only not Xfire a very different architecture X1900 with the new cards, you can't even Xfire a similar architecture HD3870 with the new HD4K cards.

There were some rumours about it before launch, but ATi/AMD have been pretty adamant about it since then that this is not going to be supported in drivers neither now nor in the future.

Yes, multi monitor is fine... with any card really. Less driver issue with a similar card or even ATi card, but overall should be fine with any card for just multi-monitor support.