If you didn't read our recent overview of AMD's recent Radeon Software Crimson ReLive Edition software release, you may have missed our look at one of the more intriguing graphics-card-related utilities to come around in recent memory. Radeon Chill, as it's called, can dynamically adjust frame rates to avoid doing wasted work when the user is standing still or not moving the mouse in-game, all while providing plenty of performance and responsiveness when a user is providing input. AMD says Chill's dynamic frame metering can reduce graphics-card noise and GPU temperatures, and as a pleasant side effect, it can actually improve responsiveness to user input by leaving GPU resources at the ready when a user suddenly throws a lot of mouse and keyboard inputs at a game.
In our initial look at Chill using AMD's pre-release software, we couldn't get the feature to work quite right. We tested Chill with Counter-Strike: Global Offensive and found that the feature wanted to hold frame rates steady at around 62-64 FPS, on average. You can see that behavior in the graph above—there's little variation in frame times. That's not how Chill was supposed to work.
After the final release of ReLive, we gave the utility another shot with TR's Radeon RX 480 and found that it was working as expected. In turn, we graphed the frame times from a 40-second run through CS:GO's weapons course with Chill on and Chill off. You can see how Chill rapidly varies frame times in response to intermittent user input when I was standing still and shooting wooden targets with a lot of mouse clicks. You can also see how it holds frame times at about 16.7 ms (or 60 FPS) during periods of constant input, like running between segments in the weapons course. At the end of the run, where we're looking at the course timer while standing still, you can see how frame times climb as Chill limits CS:GO to running at 40 FPS—our configured Chill minimum.
With Chill off, the game ran around 100 FPS on average. As you might expect, the game felt more fluid overall with Chill off, but critically, it didn't feel any more responsive. In fact, you can see some spots in the frame-time graph above where our Chilled RX 480 actually seems to put out frames faster in response to user input (especially during frames 700 to 1000 or so) when compared to the run with Chill off. That result does seem to mesh with AMD's claim that Chill can improve responsiveness by keeping more of the GPU available for times when fast rendering in response to user input is needed. Fascinating.
Typically, we'd knock a card for delivering frame times as varied as these, but aside from the expected drop in animation fluidity that comes with a move to 60 FPS from 100 FPS on average, our Chilled RX 480 felt perfectly smooth and snappy in use. If you can tolerate a slightly less fluid gaming experience at times, it might be worth turning on Chill in a game that can typically churn out multiple hundreds of frames per second and seeing how it feels. Heck, your K:D ratio might even improve.
We sadly didn't have time for a full round of formal temperature and noise testing, but I'd say our RX 480's noise levels dropped from "noticeable" to "inaudible" with Chill on. For gamers who are in shared spaces like dorm rooms or offices, Chill could let them game without disturbing others. It could also limit heat output in spaces where air conditioning isn't available. TR's Kill-a-Watt showed about 160W of system power consumption with Chill on, compared to 250-260W with it off. That's significantly less waste heat being dumped into the room, and beefier Radeons might see even larger drops.
Although Chill didn't work for ReLive reviewer Zak Killian in his first round of testing, he saw similar benefits for heat and noise. His Sapphire Tri-X R9 290X normally sits at a toasty 82° C while gaming, and its triple fans do their best to imitate a leaf blower. After an hour of playing Warframe with Chill enabled, however, he reports that the card's GPU core never went above 72° C, which means the fans on his graphics card never went above 39% of their duty cycle (a speed of around 1800 RPM). At that speed, they're barely audible. He was surprised by the change in character for his old Hawaii card, and the 15% reduction in GPU core temperatures he saw even beats AMD's claim of 13% lower GPU temperatures on an RX 480.
Overall, Chill is one of the most handy and fascinating utilities we've used with a graphics card in some time now that we've had time to see it in action. If you have a Radeon, it's well worth giving Chill a shot and seeing whether you can notice a difference in perceived performance. We hope AMD broadly expands Chill compatibility soon.