I'm currently trying out the new version of Bootstrap, when using the updated grid system to segment two columns using this code (JSFiddle):
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta/css/bootstrap.min.css" rel="stylesheet"/>
<div class="row">
<div class="col-lg-4 col-md-4 col-sm-4 hidden-xs-down">
Some content on the left that's going to be smaller than right
</div>
<div class="col-lg-8 col-md-8 col-sm-8 col-xs-12">
A <br/>
B <br/>
C <br/>
D <br/>
E <br/>
F <br/>
</div>
</div>
Each column matches height, which is currently an undesired attribute for the content I'll be displaying.
I've done a search for this and found out this was not in Bootstrap 3 and was now introduced into Bootstrap 4 by default.