Nrf connect 2.3.0 dfu a lot slower than nrf connect 2.2.1

[bds]

Nrf connect 2.3.0 is at least 4 times slower than nrf connect 2.2.1 when updating a device ota.

Is this expected?

Anyone with the same results?

[run_ar]

What connection interval are you getting with nRF connect 2.3.0? If you use an older sdk (not 15) the application most likely does not ask for a connection interval parameter update. So check if that is done as well.

[bds]

With both 2.2.1 and 2.3.0 I see:

DEBUG GAP_EVT_CONN_PARAM_UPDATE time:2018-05-03T09:13:39.025Z connHandle:0 connParams:[minConnInterval:30 maxConnInterval:30 slaveLatency:0 connSupTimeout:4000]

I suppose this means the connection interval is 30ms for both?

Could 2.3.0 send less packets for every connection interval?

[run_ar]

Could you check the MTU size as well?

[bds]

MTU is 23 in both cases. We're using SDK 12.1.0.

[bjorn-spockeli]

I am able to reproduce the behavior with the SDK v12.1.0 bootloader, using one of the test images for DFU. 
As you I cannot see any difference in connection interval(15ms) or the MTU size( 23)  when examining the logs, so then we're left with the number of packets per connection interval and/or possibly DLE, but thats not metioned in the log. 

I will need to perform a sniffer trace to check this. Will keep you posted.

nRF Connect v2.2.1 with SDK v12.1 Bootloader

nRF Connect v2.3.0 with SDK v12.1 Bootloader