My laptop (and only computer currently) is a 2010 MacBook Air 11" 1.6Ghz Core2Duo, 4Gb RAM, 128Gb SSD and a NVidia 320m (pretty similar to a Intel HD 3000, memory shared with system). So it is extremely low performance compared to even base model laptops these days.
On this I can play Vanilla StarSector fine, and the Exerelin mod with lower setup settings (8 systems, 10 stations, 9 planets). I also play with a few faction mods too. Performance isn't great with a lot of fleets on the screen in campaign mode and shift pressed down (for double speed) but it manages OK (30+ FPS). Performance is fine in combat.
I have the Java 64bit JRE and have upped the memory to StarSector to 1024 - 2048, which is actually probably more important than your computers specs (provided they exceed what I listed above) for playing most mods.
Hopefully that helps