On a traffic free day, toll bridge to dun laoire exit takes about 15 minutes. In the morns theres a small bit of traffic from the toll to red cow but I find that moves quickish. Theres that much traffic once you past the red cow roundybout so Id give yourself 25-30 mins from toll to DL.
Month by month for the past few years Ive found you gotta leave the house that few minutes earlier to make it over the M50 in the same time, so whereas say a year ago if you were on the M50 by 7ish you had a good run, now its 6:30 to get the same.