I am trying to understand if the number of concurrent tcp-connections on a load balancer is a limiting factor for a "normal" web site, rather than the data throughput. 

When I look at data sheets for load balancers I do not find information on how many connections they can handle. Does that mean the number of connections is not a limiting factor, or does it mean it is too hard to tell because other factors, in combination with the number of connections, are more important?

In the end I am trying to figure out when our load balancer will crack due to too many web site visitors. It is a virtual lb, a Barracuda BBF 340 Vx, with 2 GB Ram and 2 CPUs.