http://www.viaarena.com/default.aspx?PageID=2
All VIA drivers there.
If you're comparing a feeble onboard with a real graphics card, don't expect miracles... these things are meant to run office software, not games.
If you had decent framerates on graphics of that specification, I've no idea how it managed it. Maybe the colour depth and resolution have been increased, which would naturally lower the performance.