Just tried 2 and 3 sticks and went and looked on Asus.
1 Stick: 2Gb Installed and all 2GB was usable
2 Sticks: 4Gb Installed and only 2Gb was usable
3 Sticks: 6Gb installed and only 4Gb was Usable
4Sticks: 8Gb installed and only 4Gb was usable
Went on Asus and it explained something about how the Motherboard reserved memory for its various parts and PCI-Express cards etc, but that doesn't explain why it sucks less memory when I have 1-3 Sticks installed and more then I have 4 sticks installed.. Then I read an article about older chipsets the 915G being limited to 4GB of usable Memory but still doesn't link up.