LatencyFleX: A new approach to game latency reduction

Re:LatencyFleX: A new approach to game latency reduction by duped on Monday January 10, 2022 @11:30AM (#29877282)

Many CPUs have USB support. Pin count also doesn't correlate to latency, what matters is the minimum buffer size and transfer speed.

USB can beat PS/2 for latency without issue.

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Re:LatencyFleX: A new approach to game latency reduction by WithinReason on Monday January 10, 2022 @12:20PM (#29878099)

Isn't PS/2 interrupt based, while USB is based on periodic polling?

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Re:LatencyFleX: A new approach to game latency reduction by duped on Monday January 10, 2022 @01:41PM (#29879425)

Polling is often lower latency than interrupts on modern hardware, since it can run at much finer grains and has so much less overhead to startup over an ISR.

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Re:LatencyFleX: A new approach to game latency reduction by wtallis on Monday January 10, 2022 @01:47PM (#29879560)

That's often true on a scale of microseconds, but USB input devices are polled at intervals on millisecond scale.

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Re:LatencyFleX: A new approach to game latency reduction by cma on Monday January 10, 2022 @02:03PM (#29879893)

Only in the slowest modes. It is possible to go faster than the 1ms poll rate, though it is back to interrupts:

> Transaction latency

> For low speed (1.5 Mbit/s) and full speed (12 Mbit/s) devices the shortest time for a transaction in one direction is 1 ms.[6] High speed (480 Mbit/s) uses transactions within each micro frame (125 µs)[7] where using 1-byte interrupt packet results in a minimal response time of 940 ns. 4-byte interrupt packet results in 984 ns.

https://www.wikipedia.org/wiki/USB_(Communications)

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Re:LatencyFleX: A new approach to game latency reduction by bschwindHN on Monday January 10, 2022 @07:23PM (#29885248)

Ben Eater has a good video on this:

https://youtu.be/wdgULBpRoXk?t=1765

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