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Ask Slashdot: Low-Latency PS2/USB Gaming Keyboards?

Posted by timothy on from the edge-of-the-edge-cases dept.

An anonymous reader writes "I've a cheap but low latency mouse (A4Tech) and I noticed my trusty old wired Logitech PS/2 keyboard seems at least 50ms slower (if not more) than the mouse when I test with those reaction time sites. I even increased finger travel distance over my mouse button to make it fairer and the difference still remains. So either the tests are slower with keyboards or my keyboard is high latency. Assuming the latter any suggestions for a good reasonably priced gaming keyboard? Extra function keys might be nice but since my hands aren't big what would be better is being able to output a custom key/combo if you hold down (special?) keys while pressing another key. For example I could configure it so if I hold down "Special Key 1" with pinkie or thumb and press 4 it actually outputs 9, and if I hold down shift as well it outputs shift+9 (and not just 9). Being able to replace the capslock key function and have it behave as another key (or a special modifier) would be a bonus — I've never needed capslock and have probably used it more by mistake than for its normal function, or to test how badly a PC has hung."

3 of 177 comments (clear)

  1. You're testing wrong by guruevi · · Score: 5, Interesting

    There is not a single modern keyboard that has 50ms latency. You (humans) have that sort of latency.

    As far as response times, all you need to do is increase the poll time on the USB stack, you should be able to set it to ~1-5ms, most keyboards are in the 5-10ms range. You can also get a custom keyboard which is used for psychophysics, they run about $300 and have a guaranteed sub-ms latency. But there must be some firmwares out there that can achieve the same for cheaper. I've tested Arduino Leonardo to about 1-2ms latency (also for psychophysics experiments).

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  2. Re:so this...... by dyingtolive · · Score: 5, Insightful

    At least it's a nice change from the "do my job for me" Ask Slashdots.

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  3. Re:50 ms? by Anonymous Coward · · Score: 5, Informative

    USB latency is nowhere near 50-100ms, more like 1ms for a low-speed/full-speed device (which most HID devices are). a high speed device could be polled at 8*125us.

    You'd probably need the lousiest USB controllers and a horrible CPU to get anywhere near what you're describing.

    Disclaimer: I've actually worked on USB Host Controller and Device Controller drivers in embedded environments