^^As I said, I made room for the data, and my experience with playing Insane maps vs tiny/small maps is equivalent on the same computer - both take approximately the same time for turn completion and all other activities. Such suggests that my computer could handle "all of the data that is required of a large map" and that, perhaps, this claim by GC3 that my cpu could not do what it is clearly able to do is a bug.
Ok, but with how many turns in, with how much going on on the map? This is just a guess, but here's the thing. For the AI to complete a turn, it needs to evaluate all of the variables with which it can interact. This is easy on a small map, or on a large/gigantic/titanic/whatever map where the AI doesn't "see" very much. But what about when you're 300 turns in and all of the AI players are spamming the whole map with ships/starbases/etc? Each AI could possibly need access to more data within its observable universe than fits in your RAM. In which case each AI routine would need to read from a swap file (if swapping is allowed, if not then the program might just run out of memory and crash) instead of your memory, which would be magnitudes of order slower.
I would suspect that the game would be running along just swimmingly until at some threshold turns would start to take 20 minutes. Stardock has probably been conservative with guessing the maximum amount of memory that "galaxy size X" could require, and you haven't exceeded that conservative guess yet - so you haven't experienced a crash. But imagine from their point of view, having a lot of players playing on the biggest map they can, and then by turn 200 or 400 or whatever (after investing hours and hours of play) their games consistently become really slow and unstable -- it really would be a terrible experience.
Their experience from WOM was that people would click through the startup where a warning would say "you are using old video drivers and these will cause your game to randomly crash" and then they would complain non-stop about their game crashing -- even though the game itself specifically told them that this was what was going to happen. The lesson they probably learned was that it would be better to just make people update their video drivers than let them play with old ones.
Look, I'm not saying that you're wrong - I'm just saying that Stardock has to be realistic about the behavior not of you, but of the 98% of people out there, is all - and they have probably thought through the memory requirements quite extensively (since this is probably the biggest bottleneck to people playing the game these days (everyone's multicore, everyone 64bit now)), and came up with those restrictions for a reason. As things become optimized better it may very well change - this is beta after all - but we'll see...
Yours is a very fair suggestion (btw), and there may even be able to remove the memory restrictions altogether with a mod, or in one of the data files..
cheers
edit:
2) I have made room in my computer for 8 GB, yet the game still claims I have only enough GB for a tiny/small map; and
I was not responding to this issue - this sounds like a bug, but rather to the larger memory/galaxy_size issues more generally. cheers,