This is a strange situation you have there. I can only suggest that you
don't have a well supported video card, or you have non-optimal options
for e.g. filesystem, software selection (e.g. a heavy weight window
manager on a resource starved machine)

It all comes down to the hardware you have, what linux software you're
running, and the drivers and tuning options. With the right (wrong)
drivers and tuning options, linux could look really bad. Obviously it's
not that way for most linux users, or they wouldn't be using it.