What is your bottleneck?

1. JMeter needs to be properly tuned for high loads, make sure to follow JMeter Best Practices and recommendations from 9 Easy Solutions for a JMeter Load Test “Out of Memory” Failure article.

2. Your operating system needs to be tuned as well in particular:

   • enable tcp_tw_reuse
   • decrease tcp_fin_timeout
   • increase ip_local_port_range

3. If you're still hitting CPU or RAM limits consider using i.e. Tsung which is known for producing higher throughput from the same hardware. But be aware that you won't be able to create more than 65535 because this is the maximum number of TCP ports