[raverbashing]

The unit gain (for an OpAmp at least) is related to the bandwidth, the gain decreases linearly (in the dB scale) as the frequency goes up.

You want to be looking at the -3dB range to know +/- the actual useful bandwidth

[theon144]

Okay, but I'm still confused as to why would you compare it to AVR frequency; was that just a random comparison ("this car goes so slow you could outrun it") or would the frequency of a MCU clock being higher than the bandwidth of an op amp ever be important?

[raverbashing]

Correct, the comparison makes no sense

> would the frequency of a MCU clock being higher than the bandwidth of an op amp ever be important

Unless you specifically want to capture the analog waveform of the clock signal of that processor, it is unimportant