noHC=yes is inserted by cfgmaker not only when HC counters are unavailable, but also when interface has not yet seen any incoming traffic (ifHCInOctets=0).
Thus every unused interface initially gets noHC=yes, causing it to show bogus graphs when traffic starts to flow. After next cfgmaker run, it switches to HC counters, making huge spike in the graph.
noHC=yes is inserted by cfgmaker not only when HC counters are unavailable, but also when interface has not yet seen any incoming traffic (ifHCInOctets=0).
Thus every unused interface initially gets noHC=yes, causing it to show bogus graphs when traffic starts to flow. After next cfgmaker run, it switches to HC counters, making huge spike in the graph.