OK to put an x8 Geforce video card in an x16 slot (Optiplex 790)?

I want to put a Geforce 630 Rev.2 card in my Optiplex 790 with Windows 7, but it wants an 8x slot and mine is 16x. Will it be OK? Just want to be 100% sure as I can't return the card if it won't work.

I want this card as it's cheap, only 25W and has 384 cores! Seems ideal for me.

Link to the version of the card: http://www.ebay.co.uk/itm/Palit-NEAT6300HD46-2080H-PALIT-2GB-GEF-GT-630-DDR3-SILENT-/380742818658

Thanks for any help :-)