Laptop video cards are a bit misleading in their names. You might think the GTX 980M is comparable to the desktop's GTX 980, but the performance is actually quite different.
How different? Well, NVIDIA claims that the past few generations have "closed the gap" between mobile and desktop versions of a given GPU, but Linus Tech Tips decided to see what the actual difference in performance was on the latest cards. The results are not altogether surprising, but useful to know: the desktop GTX 980 gave 30-40% better performance than its laptop counterpart — lining up with NVIDIA's claims. The real lesson here is not to ignore that M — the 980M and 980 are vastly different cards when it comes to actual performance.
Of course, because it's a laptop part, that lower performance also comes with a higher price, which is why — unless you're doing a lot of on-the-go gaming — we recommend getting a non-gaming laptop and getting a dedicated gaming desktop instead. In fact, it's often cheaper to do so — even though you're buying two computers instead of one.
Check out the video above for the full results.
GTX 980 vs GTX 980M Apples to Apples Comparison [Linus Tech Tips]