The rendering concurency (burst limit) is set to 10req/sec by default. This burst limit controls the number of rendered requests you can start each second. For example, if each rendered request takes 25 seconds to complete, and you are consistently sending 10 requests per second, you could have up to 250 rendered requests running concurrently at any given time (10 requests/sec * 25 seconds). If you need to handle more rendered requests concurrently (Enteprise users only) please contact our support team for assistance.