Ethernet performance - old NIC vs new?

[pdeinc]

Are there any significant differences in NICs? I recently had a lightning strike take out my switch and the onboard ethernet in my PC. Nothing else in the PC appears to be damaged and I had an old NIC that I installed. I disabled the onboard ethernet in the BIOS and replaced the switch.

I now have connectivity problems that make me suspicious of the old NIC I'm using. All I know about the card is that it also has a BNC connector for that type of network connection, so I know it's fairly old generation. I can use another switch without any difference which is why I'm suspecting the NIC. Any thoughts?

FYI The typical problem is downloads will halt part way through and opening new web pages often never happen or take forever to finally start. Once started, the speed of opening the page is as it always was. If I run a tracert to the website I'm trying to access when it's sitting waiting like this, I often get an error of unable to resolve target address. Only this computer displays these symptoms and did not before the hardware changes

[pdeinc]