Round Trip Latency of xCORE-200 Multichannel Audio Platform Topic is solved

[dkybchoi]

Hi ,
I am a new developer with XMOS platform. I am now checking the round trip latency of xCORE-200 Multichannel Audio Platform running with sw_usb_audio-[sw]_6.15.2rc1.
I used MAC Mini and Studio One as HOST. The round trip latency ( from Physical Input -> XMOS -> USB -> Studio One --> USB-> Physical Output ) of xCORE-200 Multichannel Audio Platform (xCORE-200 MC Audio 2v0 ) we measured is around 8.8ms .
But what I found in the xCORE-200 Multichannel Audio Platform 2v0 Hardware Manual.pdf. that "The guaranteed Hardware-Response™ times of xCORE technology always ensure lowest latency (round trip as low as 3ms), bit perfect audio streaming to and from the USB host or network."

My question are :

1. What is the testing setup to get the round trip latency as low as 3 ms ?

2. It looks my measured result is incorrect. What is the possible problem area ?

Thank you very much

[larry]

3ms refers to device-only round-trip latency, i.e. output to input

It's much less useful when you include the host, because the host is such a big non-realtime system

[dkybchoi]

3ms refers to device-only round-trip latency, i.e. output to input

It's much less useful when you include the host, because the host is such a big non-realtime system

Thanks for your prompt reply

[Ross]

What sample rate are you running? Try 192kHz.

Those figures were achieved on OSX.

The latency though the device in the order of < 1 ms (roughly speaking 2 USB packets each way and DAC/ADC delays), the rest is host.

[Ross]

If you are interested here is a snippet from an internal document i authored some time ago regarding latency.

[dkybchoi]

If you are interested here is a snippet from an internal document i authored some time ago regarding latency.

Thanks for your sharing