Farming on Celeron J3455 @ 1.5GHz (4 cores)

[gallersd]

I am farming on a NUC with Celeron J3455 @ 1.5GHz (4 cores) running chia 1.1.5 on DEBIAN
mounting approximately 450 plots from 3 different NAS via smb and nfs both.
Additionally I have 3 remote harvesters providing another 800 plots to the NUC farmer.

In the process table I see chia_daemon, chia_harvester, chia_wallet, chia_farmer and 4 instances of chia_full_node.

It seems that one of the chia_full_node processes uses 100% of one CPU core.

Does this mean the Celeron is too slow for farming and I should migrate to a faster farmer ???

BTW in the log I find (examples):
2021-05-18T15:57:20.949 full_node chia.full_node.full_node: ERROR Consensus error 124, not disconnecting
2021-05-18T16:05:20.798 full_node chia.full_node.full_node: WARNING Wasn't able to add transaction with id 1977fbd23af553fdc2a57fe8e5803deca27695e93d51b6d8a2df5cd23d7fbae1, status 3 error: Err.DOUBLE_SPEND
2021-05-18T16:06:35.341 full_node chia.full_node.full_node: WARNING Wasn't able to add transaction with id 5e0fd02fa737a16dd9252f00973c1de56ebd70a947592925f1389673e4a78c2a, status 3 error: Err.COIN_AMOUNT_NEGATIVE

Any comment is appreciated ...

[gallersd]

Update: I checked again with mpstat.
Average overall CPU load (AllCore) is at 35%
Single CPU core 100% peaks are below 5 seconds.
Not so concerned anymore - but there seems room for threading improvements in chia_full_node process ...

[gallersd]

Update: Installed 1.1.6 and CPU load now only 30% of version 1.1.5

Hope to farm some XCH now ...