Will an old network Card effect my broadband speed?
Yes. It effects. Latest/new network cards transmit signals at a rate of a Gigabit per second (1,000,000,000 bits per second) compared to old cards with 10 or 100 MBs per second which may slow down your Internet considerably. (we call it as bottle necks)
To know the speed of your card check 10/100 Mb, 100/1000 Mb or GbE written on each card.