An expensive NIC expansion card could possibly provide better latency and slightly better throughput, but nowadays it's unlikely to be worth the money.
Ok,Ty guys.I have a new PC and just wondered if it was worth re-installing my other card,which is only a year old(card).Will leave it as is,connected to the MoBo.
A long long time ago, people would get a good add-on card instead of using built in ones, because those built in cards used a lot of the CPU power, but now in days, it doesn't really matter, at all.