Whenever I have a decent sized fleet (25+ ships), things don't lag, until I tell them to move. As soon as the movement (or action if you will) lines appear, the game starts to lag. Doesn't matter what the lines are doing or the circumstances, they just cause lag. The funny thing is that if I select another fleet in a different star, the lines go away, and the lag ceases. I don't think it's a pathing horder, but rather a graphics horder.
System Specs are:
Windows XP Pro (tweaked for performance)
P4 3ghz (overclocked to 3.6ghz)
ATI AIW X800XL 512mb RAM(overclocked)
3gig DDR RAM
300gig Maxtor HDD
All drivers and updatable hardware-software stuff up to date
I'm running on 1400x900 resolution, high textures and the unnamed menu to the far right of the graphics menu is at none.
Not a big deal at this point for me - the ship AI seems smart enough to handle what I put it through, so I barely have to touch them............. but still....