Intel DP45SG (Serie Extreme), (8GB RAM x2 (4GB each tablet)
3 beep is problem of the ram.
U cant use 4gb modules on your motherboard. your model of motherboard only allows ddr3 to 2gb max per slot! (4x2gb) total 8gb max.
BUt take care because other problem is:
that board only supports two-sided rams (chips on both sides) the tendency is to reduce the number of chips and the current Rams are one-sided.
sorry, my english is bad. I have your some motherboard and I went crazy looking for the right ram, and can not find them and I chose to change my motherboard. Is old...