They are usually backwards compatible, which means it'll work but at the slower x4 speed - not that you'll notice any difference.
What motherboard is it going to be exactly - make & model? It would be much better with this info. G
Surface Pro 5 News - release date, UK price, features, specs
Gear VR vs. Daydream: Which delivers the best VR experience?
Best Mac antivirus 2017
Synology invites you to visit them at Insomnia on 26th – 29th August. Book your tickets now and visit Synology.