Without editing the video will be rendered in exactly the same way as with the video card if you only going to convert.
Adobe Premiere uses the graphics card only for effects, but in the "effects" include such simple things as changing an image size or frame rate.
TL;DR: it depends on what you intend to do in the premiere. Just cut - normally, if the correct sequence settings when you create a indicate. If color correction and other pleasures - will slow down greatly.