Wading into the stream
Actually using ReLive is as simple as opening the app you want to capture and pressing the appropriate key combination. A little notification will pop up in the top-right corner, and away you go. Alternatively, if you can't remember your key combo, you can press Alt+Z to bring up the in-game toolbar. From there, you can start recording, streaming, or save a screenshot. There's a settings option on the toolbar too, but aside from letting you choose which corner the recording indicator occupies (including none), it simply duplicates a few of the options from the ReLive window in Radeon Settings. The Alt+Z hotkey is configurable along with the rest of the hotkeys, thankfully.
As someone accustomed to streaming using Open Broadcaster Software, ReLive is incredibly easy to use. There's not much of the way in configuration, and while that does mean it's a good bit less powerful than OBS, it also "just works." So far, I've been able to load up any game (Dark Souls III, Doom, Warframe, Phantasy Star Online 2, Overwatch, and Tomb Raider among them) and start recording or streaming with a few keypresses. That kind of convenience is worth a few sacrifices. ReLive supports a simple camera overlay and a custom image overlay, too, letting streamers personalize their broadcasts.
Surprisingly, one place ReLive doesn't require trade-offs is in regards to the video quality. Historically speaking, streamers have avoided using hardware video encoders because the quality compromises they make often result in a nigh-unwatchable video stream. I tested ReLive with my standard streaming settings against the gold standard: Open Broadcaster Software and its x264 encoder. Unfortunately, I don't have a machine handy to test ReLive's direct competitor in Nvidia ShadowPlay, but I did test my Core i7-4790K's Intel QuickSync Video encoder. I recorded several runs in Dark Souls III between two bonfires while streaming at a 4.5-Mbps bitrate. Flip through the images below to see a capture from each encoder.
The differences between these encoders are pretty minute, but we've pored over them and all agree that while the x264 software-encode looks the best, the ReLive capture isn't far behind. Intel's QuickSync is the clear loser here. It arguably has the sharpest images in scenes without a lot of motion, but it really falls flat in scenes with a lot going on.
Here's a short video sample from ReLive:
And here's a sample from QuickSync:
Finally, here's a look at a sample from the x264 encoder:
The relatively high quality of the video capture is all the more impressive in light of the fact that ReLive has almost no impact on the game's performance. Even on my beefy Core i7-4790K with 32GB of RAM, and even in a not-particularly-CPU-heavy game like Dark Souls III, the weight of encoding an HD video stream in real time with OBS has a significant and immediately noticeable impact on the smoothness of gameplay. Switching to the QuickSync hardware encoder helps somewhat, but by comparison, ReLive is barely noticeable. Of course, we wouldn't be The Tech Report if we didn't back up these numbers with some hard data. Check this out:
Dark Souls III is a little weird in that it has a 60-FPS cap, but our results still show us what we need to know about the effects that video capture has on performance. Encoding using QuickSync causes the game to spend 17% more time under 60 FPS. By contrast, ReLive is barely any slower or rougher than playing without streaming, at least on our test system. (AMD reported larger performance drops with its own test system and 8GB of RAM).
The red team says ReLive is so efficient because it sends the game's framebuffer to the encoder in hardware. By comparison, according to AMD, OBS does the same thing by hooking into the game software and setting up its own 3D context. That means OBS and the game are competing for the driver's attention, which causes the larger performance hit.
Ultimately, I've been very impressed with ReLive in the short time that I've used it. In fact, it's very likely I'll be sticking to ReLive as my encoder of choice when livestreaming in the future. x264 is undeniably higher-quality, but the drop in smoothness can be a real problem. Remember, for these test cases I was merely dashing past enemies in mostly-idle environments. In a real gameplay situation with multiple actors in combat, the impact from video encoding can be all the greater. Also, as I mentioned earlier, Dark Souls III is not especially taxing for the CPU. Other games that hit the CPU harder (like Grand Theft Auto V) will benefit that much more from ReLive.