I'm running my first ever marathon in two days and want to finish in under 3 hours. From experience, for a first time marathoner is it better to just turn off the mile split setting and just not pay attention to my splits at all? Or is it better know my pace so I can slow down if going out too fast?
Set pace alerts that start out about :05 per mile too slow, and have them speed up gradually over the course of the race.
Mine let's me have 3 data fields on the main screen. I do distance, pace and average pace. Seems like everything I need to know
Consistent with the nothing new on race day rule, I'd go with whatever settings you normally use. Personally, I like to know my pace so I will turn on the auto lap feature and view current lap pace (in large font) and overall pace and overall distance (in small font). Your splits will probably be just short of the mile markers on the course but if you are diligent about running the tangents in won't be too far off. Good luck. Go out slow.
On my Garmin 225, I set it like this for races (and other times as well):
Autolap at 1 mile. No pace alerts because they're annoying as heck.
Screen 1 (can't change): Total distance (not usually useful unless you lose track), elapsed time, current pace (not useful)
Screen 2: Lap distance (not all that useful in a race with regular mile markers), heart rate (useful for me to make sure I'm not getting into a hole too early), lap pace (most accurate way to keep track of pace).
When the race starts, I keep an eye on the lap pace to make sure I'm not going out too fast. When the time shows for each mile split, I check to make sure I'm on pace and not speeding up too soon. Periodically I'll check my HR to make sure it's something reasonable.
I'll only switch to Screen 1 in the last 1-3 miles (depending on race length) if I'm trying to hit a time goal. At that point, it's more important to know the elapsed time and what kind of pace I might have to hit to get my time goal, and at the end of the race, I don't care about HR anymore.
For mile races, I turn off everything except elapsed time.
Just wanna say that I really like having the "lap pace" setting on that one of you suggested. Along with that I had lap distance and lap time. Didn't ever look at elapsed time (except for at 13.1) but could kind of guess what side of my goal I was on by the end so I didn't worry about it. And yeah I ended up breaking 3 so yay me I guess! (obviously I don't think the watch had much to do with it)
Congrats.