I have a HTTP SSE endpoint that will be streaming data at around 1ms frequency. This data is a JSON payload that needs to move dial gauges, plot lines, etc. on a dashboard. Assume close to dozen or so widgets on dashboard that need to refresh at 1ms frequency. I have tried Node-RED dashboard. I noticed that, at 1ms, only one dial gauge refreshes and others freeze.

In case of Node-RED, or in general, is there some limit that exists for refresh of UI widgets at such high frequency? What is the design approach for the UI that can refresh at such high frequency?

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  • 4
    Your monitor refreshes at probably no more than 144 Hz. I find it very hard to believe you need to refresh the data at 1000 Hz. Commented Jul 8 at 6:23
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    The human eye is not capable or registering the changes at a rate of 1 kHz. The limit is somewhere between 20 and 50 Hz. And I also don't believe an analog gauge would be able to move fast enough to show spikes that last only 1 or 2 ms. Have you done a demo to the customer with a single digital gauge showing real, unfiltered, noisy measurement data at 1 kHz? They might not realize what they are actually asking for, because I expect the needle to jump around more than they are used to seeing. Commented Jul 8 at 6:57
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    it's a tricky question, i can see that my chrome runs at 100+ fps and that SSE can run to millions of events per sec and that Node-RED should be fine barring single threaded ness. With the freezing, that suggests the js is breaking, you should ask on the Node-RED dashboard forum. But also you need to do some benchmarkign of your app, measure the network and cpu etc,
    – Ewan
    Commented Jul 8 at 9:17
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    practically speaking, see if you can get it to work at 100Hz and they prob wont mind
    – Ewan
    Commented Jul 8 at 9:19
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    For the other commentors, I would caution you against assuming "1 ms frequency" means each guage or graph updates every millisecond. It it is unclear, but I interpretted that to mean "some sort of information is coming in every millisecond, but not necessarily information for ALL guages." Commented Jul 8 at 13:27