kog :
what does 512mb 1rx8 on ram stick and does spee up my computer
NO that specs does not speed up your computer....what speeds up your PC is the RAm's operational frequency (****Mhz - written in the ram level) and the RAM size (*Gb -written in ram level too). By the way why are you using so old and small rams as 512 mb ?
The spec 512mb 1rx8 / 64m*64 / 128m*4 / is used to differentiate between low density ram (Unbuffered and genuine) and high density ram (Buffered and usually unbranded )