There are different reasons for "lag":
a) caused by an outdated graphic card having issues displaying graphic complexity
b) caused by an outdated processor having issues calculating modelled complexity
Concerning specs of your hardware, you should always check a game's requirements before downloading it.
2 GHrz Processor, 2 Gig ram, Radeon HD 4800... Min Specs require... 1 GHrz Processor, 512 Meg ram, and ATI X1600. Sweet I can definitely play this game!
If you're not sure about a video card, you can always check the year between the oldest card that's mentioned as the minimum and the required for the maximum; being above maximum is plausible, but it may cause support problems (depends on the game). You can double-check your min specs here (at the bottom):
http://www.planeshift.it/about.htmlMy issue, Computer-based lock-ups from a dead RAM stick (512 Meg Ram stick died about a month ago... I didn't realize my computer was trying to utilize it for weeks); it's out now, but still, just be aware of computer and internet problems, those are the main reasons why games will not work (aside from the bugs that are being worked on by the team, remember that Planeshift is declared to still be in the Alpha stage)
