ble_app_uart is too slow for IOS,how to fix it?

[qoboty]

I use ble_app_uart of IOS,but the Tx speed is about 200B/s(send 20B for 100ms), why ? how to speed up to 20KB/s ? Thank you!

[qoboty]

Here is Connection Interval : #define MIN_CONN_INTERVAL MSEC_TO_UNITS(20, UNIT_1_25_MS) #define MAX_CONN_INTERVAL MSEC_TO_UNITS(75, UNIT_1_25_MS)