Hey everyone, I have decided to get two of these cards http://www.newegg.com/Product/Product.aspx?Item=N82E16814102868 deciding they give the best bang for buck with dx11 and all. I hear these cards are overclockable like a tonne. But I dont have the first clue how to overclock!, would i need liquid cooling and stuff to keep the system working, what programs are there for overclocking, do I have to tinker with my bios and voltages? and most importantly, if I overclocked them both, how would this impact framerates? thanks guys

Well, ATi cards use AMD's Catalyst Control Centre for managing them, which includes basic overclocking.

Using ATi Overdrive, in CCC, you can just slide one bar up for the memory, and another for the GPU itself (it looks something like http://i.imgur.com/TL2KW.png , though I'm not quite sure how it'd look with two cards?) It is somewhat limiting however, and there are third-party tools that allow you to push them further.

Given that you're looking at the VaporX model, which is itself a very good cooler, you shouldn't really get another cooling solution.

Do you actually need to OC them? First see whether you can play the games you want at stock. If it's unplayable on dual 5770s then a slight OC won't change much and a major OC is not worth the risk.

But, if you must OC, don't adjust voltages, and don't go more than +50MHz even if it looks like it can take it. You want complete, guaranteed stability. Also be aware you'll never be able to return it under warranty, not even for a different issue.

What Soleron said, only I'd go so far as to recommend against running two cards in CrossFire. Quoted from my PC building thread:

"Generally, when faced with the choice between two lower-priced cards in SLI and one higher-priced card, you'll always want to go with the second. There are three main reasons for this. First, driver compatibility for SLI/Crossfire across most games sucks. You'll often find yourself tinkering around with a game, trying to get it to work when a single card would do just fine. Second, running in SLI/Crossfire doesn't double your VRAM; two 1-gig cards running in SLI will only have 1 GB RAM. Third, SLI/crossfire currently has problems with microstuttering that can - quite literally - make playing a 60 FPS game be like playing a 30 FPS game. So while the drivers may improve in the future, right now SLI/Crossfire just sucks."

If you have $300+ to spend on graphics cards, then just get a 5850.

Actually, I didn't say that only because I'd just recommended against it to him (with many paragraphs) in another thread.

For overclocking I just use the BIOS instead of third party programs.

I don't think you can do that to overclock a GPU. CPU yes.

okay u guys have convinced me, ill just wait for the 5870 to come down in price a bit, so not much pointin overclocking then?

It's easy and painless to overclock it to the max CCC will allow, but it really doesn't provide much of a difference.

Yeah, to get an OC that makes a significant difference you need to fire up RivaTuner and something that'll stress your card (usually a game; you can also use something like FurMark, but at your own risk.) And even then, video cards vary wildly as to the amount of extra juice you can stably squeeze out of them at stock volts. Heck, even cards from the same manufacturer and model can vary. So it's sort of a crapshoot, but worth a try if you want to wring everything you can out of your card.