Biggest Map anyone has successfully played a game on?

[Grandpa Troll]

I have an AMD Athlon 700 with a 32 bit graphics card and 256 rAM, I was wondering what the largest Map size I could play on while not taking 10 minutes in between turns?
I understand that the more civ's,years and units slow the game down, just asking!

I have I believe a 220 X 400 right now, all land with 4 civs, (me,3 ai and barbs)
All is ok thru around turn 35 or so, .....

Thanks

Troll