We didn't publish DirectX 12 performance results in our recent reviews of the GeForce GTX 1080 and the Radeon RX 480. It's still relatively early days for Microsoft's low-overhead API, and we still think DX11 performance is the most relevant metric to go by for most gamers. That omission doesn't mean we aren't able to collect performance data, though. We wanted to share some early results of our benchmarking methods for DirectX 12 using Rise of the Tomb Raider as our platform. Let's dive in.
First, we used the same settings and benchmark run that we did for RoTR in our reviews. The only change was to enable the DirectX 12 rendering path in the game's graphics settings. We tested the game with two graphics cards: the Radeon RX 480 and the GeForce GTX 970.
Well, that's disappointing. A major drop in average FPS and a major increase in 99th-percentile frame times doesn't bode well for RoTR's DirectX 12 implementation. The Radeon RX 480 does seem to suffer much less than the GTX 970 when DirectX 12 is enabled, but neither card is providing a good experience at 1920×1080 with the settings we chose.
Our measures of "badness" suggest gamers should leave DirectX 12 off in Rise of the Tomb Raider, as well. Neither card spends much time past 50 ms working on challenging frames with the DX11 API, but enabling DX12 causes both cards to spend almost two seconds working on tough frames—and those hitches will almost certainly be noticeable, since the corresponding frame rate will drop below 20 FPS during those times.
Neither card produced a solid 60 FPS in our original benchmark, but they struggle quite a bit more in DX12 mode when we look at the time spent past 33.3 ms and 16.7 ms. That's not surprising, given our average frame rate results for both cards. In any case, DX12 does not provide a more fluid gaming experience.
What can we take away from these numbers? DirectX 12 puts much more of a burden on the game developer to deliver a well-optimized experience, and Rise of the Tomb Raider's DX12 implementation seems to need more time in the oven. It's certainly irresponsible to call a winner using these numbers—both cards fail to deliver a playable experience by our rather high standards. Leave RoTR in DX11 mode and enjoy it that way for now.