Journey times on the Cork Dublin route

[Fergal]

I've heard a lot about journey time padding on this route. Currently, it takes about 2hours 50 minutes for a typical journey. What is the fastest that this journey could be done at, with 3 or 4 stops, if Irish Rail decided to run the trains to their full potential, with a minimum of recovery time?

Does Irish rail need to spend a lot of money on the line to reduce journey times?

Also, could a two-hourly stopping pattern with 3 stops help?

Something like
Odd hours: stop Portlaoise, Thurles, Mallow (for Kerry).
Even hours: stop Ballybrophy (for Limerick), either Templemore or Charleville, and Limerick Junction (for Limerick).

All stops closer than Portlaoise served by commuter trains.

Really, a journey time of under 2hours 15minutes is needed - is there any possibility of getting this in the next 5 years.