PsychicShadow :
cheese9k :
Your CPU is going to be a huge bottleneck here. I'd just upgrade to a newer platform or focus on CPU/RAM upgrades.
what cpu do you recommend for my pc than
After looking further into it, the furthest you can upgrade is to a Core2 Extreme X6800. This CPU is almost 10 years old now, just like your E6400.
If you're wanting to spend much money, then a cheaper AMD build/Pentium build would serve as a huge upgrade.