Models from old computer are lagging on a newer one.

hi, i’m Fustran. i’m new to the forums, i’m pretty sure this is where you would put a question like this one.
so, as the title says, models are very laggy when they were created on an old computer.

I would begin modeling something at school (on the school computers, the are outdated and slow, but enough to run

blender at a decent speed. also running windows xp) during my spare time. once school ended, i would continue my

project at home. however, like i said, the model would be quite laggy. the model being only around 5k faces, my computer can easily handle 300k - 400k faces.

i am on windows 7, and have a powerful graphics card. (GeForce GTX 550 Ti)

any help would be appriciated, this is getting annoying.

                    thanks, -Fustran

It’s hard to deduce anything from information you provided. Perhaps sharing a .blend via so we could peek inside would help to find the problem.