I am searching how to increase the number of sent requests per second .
I used 80 threads and set a Constant Throughput Timer and Variable throughput timer and i set 10 transactions per second and i when i get Jmeter logs i see max 4 transactions per second .
I also changed the heap variable to this and i have a virtual machine with 32 GO
but when i supervise the conssumed RAM for the jmeter process , i find only 1.4 % .
JMeter waits for getting the response before sending the next request therefore the throughput (number of transactions per unit of time) mainly depends on the system under test response time.
One possible situation I can think of is that you have too few loops (iterations) defined on Thread Group level
if you don't have sufficient number of iterations to cover the ramp-up period and "plateau" you may run into the situation when some threads had already have finished their work and had been shut down and some were not started yet. So double check that you have anticipated concurrency using i.e. Active Threads Over Time listener as it is possible that you have much less than 80 online virtual users. See JMeter Test Results: Why the Actual Users Number is Lower than Expected article for more comprehensive explanation if needed.
If you follow JMeter Best Practices and ensure that JMeter has enough headroom to operate in terms of CPU, RAM, network, etc. - it might be the case that the application under test cannot process more than 4 requests per second so whatever you do on JMeter side won't have any impact. So I'd rather check your application logs, CPU, RAM usage, look at profiler tool output, etc.
