7950 one fan, two fans, three fans?

I have been looking at the new 7950's for my new build. The reference card has one fan. But then XFX has two fans on both of their models. Gigabyte has three fans on theirs. Are extra fans really necessary? I understand that the ones with more fans are generally overclocked, but can you overclock a stock reference card without extra fans, or are you asking for trouble keeping just one fan? I was thinking about starting out with two 7950's crossfire in a three monitor eyefinity setup, I don't think I will need to mess with overclocking, but I am just curious. Thanks

You can definitely overclock with the reference design. The idea with the non-ref designs is that they should have improved cooling (which includes less noise as well as better thermals) which is turn should lead to a better OC. However, that isn't really a guarantee. Many come factory OC'ed (usually at moderate levels that should be easily achievable on your own), but not all are.

There are good reasons to pick a particular non-ref design, but it should end up at the same general level of performance. You may strongly dislike loud fans, and non-ref designs CAN help a bit there (though some aren't much quieter than reference designs). For me, I always try to find the best deal when I settle on a particular card. I picked up non-ref Galax 560 ti's because they were the best price. It was just extra nice that they perform well (though not quite as well as the best, more expensive non-ref designs). Hope that helps. Cheers.

Depends what your wants/needs are.

Do you plan to leave the card stock? Reference design will be fine otherwise a non reference design might be more to your liking.

OC'd cards produce more heat. Vendors counter this by adding custom cooling solutions. What you need to watch out for are how big some of these coolers are. They may block your other PCIe slots.

The OC headroom on the new AMD cards is pretty nice. I am waiting to see what Nvidia has to offer in a couple months otherwise I plan to pick up a 7950 myself.