Hacker News Reader

Comment by byuu | Hacker News Reader

> E.g., not only do emulators introduce lag, also modern systems tend to be laggier than vintage ones.

Some emulators have run-ahead now, which removes internal processing frames from games. Combined with an adaptive sync monitor, 1000hz USB polling, and other tricks, emulators can actually respond to inputs faster than the original gaming consoles did on CRTs. It's pretty much the closest thing we have to magic.

Here's a video demonstration I made: https://www.youtube.com/watch?v=1AvOa8yt6Vc

An an article of mine explaining the concept: https://byuu.net/input/run-ahead

View on HN

> Some emulators have run-ahead now, which removes internal processing frames from games. Combined with an adaptive sync monitor, 1000hz USB polling, and other tricks, emulators can actually respond to inputs faster than the original gaming consoles did on CRTs. It's pretty much the closest thing we have to magic.

Super Smash Bros Melee has a little bit of polling lag on console (the tournament standard) due to poor coding. By removing this lag (or rather, making it configurable), you can "hide" network latency behind this lag people are used to, and online play can feel like local play.

Like you said, magic!

While I agree with you on this for the most part, aren't we going to start hitting a ceiling with what's possible to do run-ahead with?

For example, I know in that article you mention bsnes, but wouldn't it be exponentially more difficult to have that feature in something like a GameCube or N64 emulator (let alone something like a PS3 with its funky Cell architecture)?

The system setup of old devices was quite different from what we're used to now. CRT TV's, no OS in the way. Just inputs and near instant display of what was going on.

The more modern your game system gets, the harder it is to perform runahead. But it's also required less and less. Newer consoles got more 'laggy' by default, with OSes, USB/Bluetooth input processing, triple buffering and so on. So runahead requirements have become less and less to recreate experiences.

As to you examples, the PS3 was meant to be played on LCD TVs much like our current setups. I don't know how RPCS3 compares to a real console, but I expect the difference isn't huge. Dolphin (GameCube) and Mupen (N64) can emulate their consoles so efficiently that you should be able to achieve 1 frame of runahead on somewhat powerful systems for many games.

Yes it definitely would be. Every frame of run-ahead requires emulating another instance of the system. So a run-ahead of four frames means needing 5x the processing power. Generally speaking you'd only want 1-2 frames of run-ahead, however. And in practice you can usually skip video rendering during the run-ahead frames to reduce overhead a bit.

Reply on news.ycombinator.com