Try developing all of those planets and having a culture, trade and refinery on each. At that point, I think 1100 planets will cause some serious lag issues.
Its not the map that causes the problems, its developing the planets.
I find on my computer (3 years old now, so not the best), once I get past 50 developed planets (where usually the other races have another 50 mostly developed, the game lags noticeably.
I wouldnt even attempt to play 1100 planets. The trade ships alone would be enough to grind the computer to a halt long before you get more than 10% explored.
