Hi!
Conversations on game time always make me feel like a freak of nature.
My average time for 4k game is 1 hour and 30 minutes. With 30 minutes to 45 minutes of setup time.
I kid you not....
I tend to pre-plan battles. So I show up already knowing what the board is going to look like and have all the terrain picked out.
Second I have my army and composition picked out before as well.
These two are tremendous time savers and can easily save you a couple of hours of game time.
The last is very player dependent. I rarely if ever look up anything rules-wise during a game. If my memory fails I'll happily take the opponents recollection of rules and stats. I'll look them up after the game. Combine two players like this and you save a couple of hours as well.
Also, I tend to think what I will do strategy-wise in my turn when the opponent has his turn. This too saves time.
I have ran and successfully concluded games to around 25k-30 PER SIDE in 6 hours (sans setup time which was done the day before). I usually arbitrate such games and keep players moving the game along to insure it is completed in the allotted time.
When I gamed frequently I could routinely play 2-3 4k games in the course of the afternoon.
Those were the days.....
Primarch