Duh! (Don't mean to be offensive, but an old joke about SNMP, using SMMP, we've discovered the cause of the high CPU consumption and bandwidth consumption, it's due to SNMP).
Now a days, SNMP bandwidth consumption usually is a much smaller percentage, and CPUs also generally have much more overall capacity, so such issues aren't as noticeable as they were decades ago But, if you work hard enough, like polling a lot of data, you can relive the joys of decades past.
Another very old joke, that pertains, might be "Patient - doctor it hurts when I do this. Doctor - don't do that".
So, is there anything that can be done, beyond replacing hardware with more powerful devices? Yup, much as we did decades ago, think carefully about how SNMP should be used. For example, as suggested by @MHM Cisco World , traps do on device monitoring and notify SNMP management of a threshold crossing rather than constant polling data. Or, think carefully what data you really must see and how often.
