Downloaded installation, write it to card and started from this. Changed CPU governor to ondemand, to get higher speeds. Minimum CPU freq was 1000MHz and max was 1500MHz. Everything was fine and quick. After upgrading (https://beagleboard.org/upgrade) max CPU frequency is 400MHz and cannot be changed. No matter what I set as max or what governor I will try. System is extreme slow.
Tested few times from beginning - CPU speed will go down after kernel upgrade (sudo tools/update_kernel.sh). Tried both recommended version and also Alfa Testing, with both with same result - CPU speed is locked down to 400MHz.