Grid 2 is quite CPU-bottlenecked when pushed to high framerates, even when running at maximum detail settings and 4x MSAA. Obviously, however, more GPU power still provides a boost, so there's a lot going on in this game to complicate the results. Windows 8.1 actually outperforms Windows 10 on the GeForce card, while taking a back seat to the new OS on the Radeon card. We'll call this one a split decision and move on.
Ah, Tomb Raider. Fun to play, easy to benchmark with. That's because it is almost a pure GPU benchmark. And this time around we see unambiguous results: Windows 10 trounces Windows 8.1 on both test cards. This is the kind of performance boost you only expect to see when upgrading a video card to a much more powerful model, so it's a very welcome result indeed.
Metro: Last Light
OK, Metro doesn't offer up very interesting results. First of all, we should mention that because the minimum framerates reported by the built-in benchmark are notoriously inconsistent, we've simply excluded them here. And in terms of averages, we get the opposite result that we saw in Grid 2; Windows 10 helps the GeForce card, while slightly hurting the Radeon model. Overall, we'll have to call this one a draw as well.
The running tally so far: 1-0-2, with one big win for Windows 10 and two ties.