Hi, I have a Intel Celeron 2.6 GHZ and I don´t know if I should upgrade to a Pentium 4 2.8 GHZ. Will I notice a big upgrade with the Pentium4?? Or my celeron is okay? I use my computer for casual gaming and i hate low frames per second in my games. I have a Intel D845GVSR motherboard with a socket mPGA478. Please help! Thanks..