I'm still wondering

I'm going to be upgrading my current system by replacing almost every single part in it and I was planning on going with an entirely AMD build.

But that bit is not exactly the most important, what I wanted to ask was this: is the ATI Radeon HD 5970 actually effective enough in enough games to be worth buying used off ebay for around the same price as the current AMD Radeon HD 7870?

I've been looking at some benchmarks and theoretical statistics for the two cards and the Radeon HD 5970 always comes out ahead because, well, it's beastly and has two of the highest-end GPUs that they had back then stuck to one PCB. But the main issue I've been considering is how effective is the on-board crossfire? Is it practically a guarantee, or will half of my games and other GPU oriented tasks be played out on only a single Radeon HD 5870?

Do you have a 5870 or a 5970...? Also, here is a pretty general rule that i like to follow. if you buy mid range (x770-x870 or GTX x50-x60) you can normally skip out on one generation of cards, so to use myself as an example a GTX 465 allowed me to skip the 5xx series, but I needed something from the 7xxx/6xx series since i couldn't handle games like sleeping dogs/arma3/max payne3. The nice part about buying top end cards is that you can skip over two generations at a static resolution, so the next upgrade you would need make would be an 8xxx series had you bought a 5970 back when they came out.

So right now a 5970 is a viable option especially in games that scale crossfire well, but you'd be upgrading to the 8xxx series really soon.The degree to which crossfire is benificial really depends on drivers, and individual game optimizations (bf3 is a good example) so i can't really tell you how good it would be in a general sense.

As for the onboard crossfire, it's the same as if you had two physical cards, so any games that don't take advantage of crossfired cards will only be taking advantage of a 5870 which can still flex its muscles but can't handle this current generation of detail.

What you should do is either buy a 7870XT since the 8xxx series is delayed, or save up and buy a 7970ghz since the closer we get to Q3 the lower the average price will be on that card.

Also if you're upgrading a system right now, be aware that ram has gotten pretty expensive. It's kind of wierd upgrading piece by piece because you'll be talking about your rig and be like, "i sunk 3 grand into this beast" but it'll perform like a $1300 pc. Good luck :D

I don't have either, but what I meant is that the Radeon HD 5970 is actually two Radeon HD 5870 chips crossfired onto one card. Well, they aren't exactly 5870 chips, but they are a little closer to that than anything else.

What I was mainly looking to ask is whether I should get a 5970 because it should outperform a 7870 XT, or if I should get a 7870 XT because the Crossfire may not always work on the 5970. I was asking if anyone had any information pertaining to how reliable the crossfire was on the Radeon HD 5970.

And I won't be upgrading right now, it'll be another four months or so before I upgrade, but I may be buying a couple pieces before then when I get my tax return in. So I'll have enough of a span of time to find some really good deals on products like RAM. I've actually been keeping a watch out on the Patriot Viper 3 RAM (which I suggest everyone do) because they've been having sales off and on for their 2133 MHz RAM. And I've been recommending it for other people's builds int he past month because an 8 GB pack of it has been around $56-$60. It has since gone up again to $82 for the black ones, but it does go on sale more frequently, I find, than most brands. Plus it is absolutely beautiful RAM, with black PCB and everything.