Varying frame rates have been a hot topic in the past few years, but do you know the real benefits of a game running at a faster frame rate? IGN spoke with Mike Bithell, the developer of the upcoming stealth-'em-up title Volume , to better understand frame rate, its importance, and why games run at 30 or 60 frames per second instead of something in between.

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Frame rate is linked to monitor refresh rates, Bithell explains, which traditionally are 30Hz and 60Hz."It's a historic thing. The refresh rates on monitors were standardised a long time ago that they were multiples of each other. So you know how data is either 2, 4, 8, 16, 32, 64, 128, 256, 512? They double up. It's a similar thing with frame rate, it was basically the screen refresh rates."Hypothetically, you can run a game at 45 FPS, but as Bithell points out, when designing a game you wouldn't want to go from 30 to 45 because it would involve animating one-and-a-half frames. Instead it's far more effective to double the frames."In fairness most of the modern engines are pretty frame independent – which means the code is run every frame in a lot of cases – or it's run at physics intervals which are independent of frame rate. But very few games now are making per-frame calculations and movement, so whether you're playing Call of Duty at 12 FPS or at 60 FPS, the game's going to interpolate: the last frame took 'this' long to render and I want 'this' cycle so I need to move 'this' far forward. It's not [that] you run slower if the frame rate's worse."Bithell recalls a racing game which ran natively at 30 FPS, but after modders got hold of it, it was changed to run at 60 FPS. The problem was that it wasn't frame rate independent, meaning at 60 FPS the cars doubled in speed.The biggest concern is when a game starts dropping frames. When the eye has been trained to see something in a specific way, be it 30 FPS or 60 FPS, the occasional dip in frame rate stands out much more. One of the reasons developers lock a game at 30 FPS is due to such dips - it's better to have a solid game running at 30 FPS than one that can run at 60 FPS but doesn't always."Often when you see [frame dips] in a game you're playing at 60 FPS it'll dip to maybe 40 FPS, but because your eyes have grown accustomed to 60 the illusion's lost. If it was a solid 30 FPS it would look smoother than 60 FPS dipping down. That's why a lot of games lock in frame rate, even on PC, so they actually say "You know what? We're not going to let anyone play this game faster because we want to ensure consistency and frame rate rather than just hitting aforementioned peaks."The ultimate question is does it really matter? Undoubtedly, a game running at 60 FPS will look smoother if everything's working as it should – providing the power's there to back it up – but that's not always the case. If a game has a lot going on in a massive environment, sometimes it's better to hit a smooth 30 frames per second than attempt to create something that could be hindered by modern hardware."Frames per second is really tricky. FPS is actually a much, much bigger deal than 720p/1080p, because what you're doing is effectively rendering twice as many pixels, which is massive. The key thing here is you have to maintain that as well. For example, if you're making a historical game set in France's open-world, and you're making it 30 FPS [there's] no way in hell you're going to be able to bring that game up to 60 FPS because you'll have optimised around that."On the other hand, getting from 720p to 1080p, although difficult, can be achieved with the right programmers. But redesigning a game from the ground up to run at 60FPS? Not so much, says Bithell. "With enough time and some very, very clever graphics programmers, it could be done. But 60 FPS is having to draw twice as many pixels. And there's also other layers to it people don't really consider; like a lot of engine's animation is locked into a frame rate."Films, unlike games, run at 24 frames per second. One of the reasons film can appear so smooth comes down to motion blur, which is something game developers have tried to incorporate into engines. Although a useful solution to frame dips, the downside, as Bithell puts it, is due to how much memory the process would consume."Motion blur is quite an expensive process; you have to save a lot of data, graphically, because you're essentially rendering pixels and storing them and throwing them back on the screen which is, depending on graphics card and platform, quite a challenge."Bithell faces a slightly different challenge with Volume. "Our biggest bottleneck in the frame rate is the AI, which we're fixing because of that, because our AI's really messy", he explains. "On PC right now, on my year-old Mac, the game runs at around 120 fps. So yeah, on console, we'll probably cap it to 60 FPS so we can get a consistent frame rate, but that's more to do with my game being really simple more than anything else, it's not about us being really clever game developers - we are really clever game developers - but that's not the reason."For more on Volume, and overly-long explanations of frame rates, keep it right here on IGN.

Wesley Copeland is a freelance news writer, but you probably already guessed that. For more obvious statements, you should probably follow him on Twitter