users are running into that problem over and over but how did those artist from a decade and prior get by with a system like an Atari 1040ST or an Amiga?
As was mentioned above, what can be accomplished "in the box" nowadays with a fast PC is a *whole* lot different than what could be accomplished 10 years ago.
ie: We're currently running quad/hex core CPUs at ~4.5GHz... compared to a single core CPU running at 1GHz.
Now factor in improvements in architecture...
Expectations are *much* higher now... and rightfully so.
The ability to effectively work with software based input monitoring was made possible with the i7 CPUs.
Yes, you could do it prior to the i7, but not when running heavy loads.
Doesn't matter what PC you're talking about, this wasn't possible 10 years ago.
I remember teching a session at a studio in Nashville, where we were multing the signal off mic preamps... (running a line straight to console - for monitoring while tracking) so the vocalists wouldn't have to deal with rediculously high round-trip latency. We had to work around the limitations of that time... there was no other choice.
You could use a 10-year old computer to run Sonar...
BUT... don't expect performance/capabilities to be anywhere close to what's possible with a current generation Sandybridge based DAW.
IOW, If you can live with the expectations (limitations) from 10 years ago... you won't be disappointed.