The capacity of a DART car is approx 50 seated and 150 standing, so an 8car unit could potentially carry 1600 passenger. If IE ever achieve 10 minute frequency, the line capacity would be 9600 per direction per hour.
The original 30m Luas had a capacity of 256, and the current 40m units have a capacity of 358. I can't find an official capacity for the new 55m units, but a back of the envelope calculation suggests it would be close to 500. I also haven't seen capacity figures for Metro, but I believe it's planned 70m trams would be used, so I would guess these would have a capacity of around 650. At 3 minute frequencies, Metro should have a capacity of 13,000 per direction per hour. You would need to get the DART up to 8 trains per hour to come close to that capacity.
