At present only 50km or 19% of the Dublin - Cork line is capable of 160km/h operation, but the improvements would save 25 minutes to achieve a journey time of 2h 20min. The maximum speed on the Dublin - Galway line is 130km/h and only 63% of the route is passed for that speed. Here the track upgrading will reduce the journey time by 33 minutes to around 2 hours.
IE has already invested in new trains capable of running at 160km/h, so the plan will not require any additional investment in rolling stock other than that already underway.