I'm thinking about upgrading my ATI Radeon 3450 to an ATI Radeon 5450. I have a vostro 220s and I'm not sure if my system an handle the card or will it even fit. Will it fit my computer and can my 250PSU handle the card? Here's a link to the card here. My last question is how big of a performance jump will it be going from an 3450 to an 5450?