Is this normal?

[patentu]

i run 2x zeus hurricane x3 on litecoin with raspberry pi and hashra pi image

Mining Session Overview (01 hrs 00 mins 43 seconds )

    65 Hardware errors
    1187 Acc. /Rej. 2 (0.17 % rejection rate )
    28.46 Mh/s avg hashrate
    28.72 Mh/s current hashrate

why so many errors like 1 error / min?
should i change chip count to 128 (default in hashra is 64)
core clock 330 mhz default,should i increase the core clock?



Thank you!

[patentu]

up!