No Manshania you're wrong..
@shirish
Two 512 MB sticks are good only if your motherboard supports a feature called DUAL-chanel mode.
NOTE:: for dual-channel mode to be effective, the modules must be identical, preferably of same make.
In dual-channel mode,the memory controller utilizes two 64 bit data channels, resulting in a total of 128 bits, effectively doubling the bandwidth to memory.
IF your mobo does support DUAL-channel mode, then the effective spped of your RAM modules is doubled, i.e if your ram module is rated at 400 MHZ, the dual-channel system will operated at a theoritical 800 MHZ..
@Manshahia please check before you post.