I bought a brand new computer which is a core 2 duo e4400 with 2 gb ram?

now my old specs were a sempron 3000+ with 1.8 gb ram and then i moved on to my core 2 duo and sure my crysis gameplay improved by something like 10 fps but execpt gaming i open all my normal applications and watch lot high definition videos and encode some short videos and the performance increase was really not so much even in video encoding cause my sempron has sse, sse 2 and sse 3 cause i thought i will see like a 90% performance increase but it really wasn't so much cause the core 2 duo really should outperform the sempron in every single thing but in most high end tasks the core 2 duo outperforms sempron but in the pmark benchmark the sempron scores 400 and the core 2 duo scores 2000 then why wasn't the performance increase that big cause there is a 1600 performance points difference in them but i really didn't see that much why didn't the core 2 duo outperform the sempron in everything.