I am taking performance data on nginx.
The client I used is h2load

Request per second using h2 is much higher than h2c. But I think it should not be as h2 is having the overhead of ssl.
I have used the command
./h2load https://xx.xx.xx.xx:4070 -n500000 -c1000 -t50 --- h2
./h2load http://xx.xx.xx.xx:4090 -n500000 -c1000 -t50 --- h2c

and at the server side config is
http2_max_concurrent_streams 600000;-
http2_max_requests 600000;
http2_streams_index_size 524288;

The h2c is getting 23008.09 req/sec and h2 96091.85 req/sec

The request is for default page provided with nginx instalation