Oh, my mistake on not reading that it was DDR. Well as aetherh4cker has suggested, check CPU-Z and take an SS of it so that we can see the specs. Please and thank you.
I figured after all that, you'll probably need a new power supply, too. And the Sound Blaster Audigy SE is no XFi, but in all honesty, any good sound card that is not integrated will take a lot of pressure from your CPU. These parts total about £280 or €400, inclusive of VAT.