ati 4770 retail and reference is different?

here is a retail pc

http://pc.watch.impress.co.jp/img/pc...1/radeon_1.jpg

here is a reference pic

http://www.pcper.com/images/reviews/700/card_naked.jpg

not sure any difference in overclocking capability.

The reference is a dual slot. Notice the difference in caps as well. I think the non-reference would be less stable at at a higher overclock as a result.

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Also, does the reference have a 3 pin fan header? Looks like the non-reference only has a two pin.