When do HMAC use less CPU power than Hash function in a MAC

When do HMAC use less CPU power than Hash function, (if it does it)
assume HMAC (Data) when Data can be from 8 to 120 byte compared with
a MAC message usingt Hash(Source address, Data) and Source address can
be from 2 to 8 byte.

Regards
Ulf Reiman

.

Relevant Pages

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