Unfortunately it seems as if the PC version of No Mans Sky is having severe performance problems on some systems at the moment. Here's a description of what's going wrong and a discussion of PC port problems.
No Mans Sky isn't working well on PC for some people at the moment. ─ TotalBiscuit, The Cynical Brit

<style>.embed-container { position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; max-width: 100%; } .embed-container iframe, .embed-container object, .embed-container embed { position: absolute; top: 0; left: 0; width: 100%; height: 100%; }</style><div class="embed-container"><iframe src="http://www.youtube.com/embed/LRkHPsZak08" frameborder="0" allowfullscreen></iframe></div>