I'm using nRF Connect v2.6.2 on windows 10 using an nRF51 dongle to update my target OTA. Target is an nRF52832, softdevice s132 v6,1,1. The DFU process takes like forever!
When using an nRF52840 dongle, DFU is much, much faster. Same when updating from an Android phone using nRF Connect; much faster then from the PC.
What is restricting the speed with this nRF51 dongle? Is there a restriction on MTU sizes, on speed or anything?