Will HD 5770 fit in N-Alvorix -RS 880 - uATX motherboard?

[cfordg57]

I have a new HP p6710f with a N-Alvorix -RS 880-uATX motherboard. I want to upgrade the video card to a XFX HD 5770 with uses a PCI Express 2.1 x 16 interface. I was told by Staples where I bought it that this card would fit and work fine with an upgrade PS.
I then asked HP Support and they told me that any card using the 2.1 x 16 interface would physically not fit the slot with is only described as a PCI Express x 16 slot. Can anyone confirm who is correct on this issue? I need have both the card and power supply here but if the card will not fit or operate correctly in this motherboard, I need to send it back ASAP

Thanks

 

[edicspaz]

I have the same motherboard and was equally concerned about installing my XFX HD6870 in my computer. Fortunately I didnt have any problems whatsoever, fit like a glove! (it really gets very close to the ram though)

 

[cfordg57]

Best answer selected by cfordg57.