replied on October 24, 2016
With Forms 10.1, the transactions per seconds to load and submit a form with 30 fields is around 25 on a machine with 2 processors and 4 cores for each processor. So with such environment, it can handle 90000 submissions per hour. With more fields, the performance will decrease. After submit, the submissions will be processed by Forms Routing Service, it can process around 10 submissions per second for a form with 30 fields, so it can process 36000 submissions per hour.
So 3000 submissions per day won't be a too high workload for Forms Server.