My desktop PC, Gateway GT 5668E, came installed with 3 Gb. of 240 pin DIMM DDR2 PC2-5300. The motherboard does support DDR2 800 MHz of SDRAM. I want to try 800 MHz, but Newegg doesn't have a category for DDR2 800 MHz PC2-5300, only DDR2 800 MHz PC2-6400. Well my motherboard take DDR2 800 MHz PC2-6400?