There are a lot of things that do this.. it's amazing. One of the edit systems I use at work (when I can't get on the Avid) runs on WinNT (one day they will fess up and reveal that this in fact stands for 'nearly there').
What version of WinNT?
I think the strength of the Amiga is not just pre-emptive multi tasking at the OS level -- it was doing it at the hardware level,
With OS shared memory architecture, AmigaOS's main strength was its task switching speed.
An Amiga with just chipram; i.e. this bus has to be shared with customs co-processors chips and CPU.
This should sound familiar to the modern PC.
In a modern PC, bandwidth has to shared with the following co-processors
1. GPU (a.k.a VPU),
2. APU (a.k.a DSP),
3. SPP, (nForce’s case) nForce 2’s SPP (Northbridge chip) is short for "Signal Platform Processor".
Thus the case for 128bit wide bus (via dual RAM channel controllers).
Of course one could plug-in dumb video and sound cards on a modern PC.
PS; An Amiga with Fast RAM and Chip RAM is effectively has dual RAM controllers (minus the “cross-bar” technology).