More of a computery question, really, but I'm sure some of you will be able to help...
I understand what latency is and, for the most part, what causes it, but why do we have it?
For example, my HD 500 is quite happy to do A/D and D/A with a whole bunch of amp modelling and FX processing in between and with no latency, whereas my decent-spec laptop can't do anything without adding latency delay.
What's the difference? Why do computers always introduce latency?