Crossfire HD6870's - Do or dont?

Hey guys I've been thinking about getting a second HD 6870 for my PC because I think I could have better performance than I currently have.
Has anyone got any experience with crossfire and would you recommend it? Or would you just recommend ditching the 6870 and get a better Nvidia card? I don't feel like spending 500 bucks or anything on it though
I saw A 6870 for around €180 (not sure if that is expensive, from what I can gather online it's alright thought I can get it for around €150 online) so it got me thinking.

Let me know

-edit
Or I could try overclocking.. Never really tried it, it's not to hard is it?

Overclocking? Doesn't that kill your PC eventually?

not really. it "can" damage it but it usually not happening.

you cannot clock lets say a CPU more then it can handel. but the risk of a malfunction increases but not much.

Just buy the crossfires dude

The reason why I haven't done any overclocking its because I'm afraid I'm going to break it, but it does sound cool to me.

Not worth the risk buy the crossbow and fire it into your pooter. xD

MERRYYYY XMAAAASSSS ALLL XXX

i still have an ati HD4870 1GB, its OC but not too much and it handles pretty much anything I can throw at it. In general the 6870s OC well so I would say grab another 6870 and give them both a mild OC.

EDIT: OC=overclock

Thanks Delta, sounds like some valuable input + I know what oc is ;D

Thank you too scotty for your em.. "valuable" input

No problem dude, on the OC front, if you go for crazy overclocks then yeah you'll fry your s**t but if you do a moderate 5-10% then you are normally safe. I use a program called MSI Afterburner to OC my 4870. The other thing I meant to say is if you're gona buy a 2nd one, make sure its the same manufacturer and card as your 1st one, eg if you have a MSI twin frozer dont go buy an ASUS one as they will have different clock speeds and vary slightly, when SLi/Xfire its better to stick with 2/3/4 of the same cards.

To the people who say it doesn't matter, yes the software supports different cards, different clock speeds, and even different GPU's (670+680 anyone), however, the clock speeds will come down to the lowest one and Xfire in particular can be a pain so why add more problems?

EDIT: a good(ish) guide to MSI Afterburner linky!

The 6870 is a 6890 with disabled feature you can flash the BIOS to 6890 spec. Google it. That's 2hy the 6870 overclock so well.

i have only ever fryed one card and it took 12 months for the aggressive oc to take its toll 35% and it took 12 months of it by then your looking for a new up to date card anyways