Nowadays modern cryptographic systems require a tremendous amount of keys. Very fast random number generators (RNGs) are needed to produce those keys in the requested time, but what to do when a solution that is already in use reaches the maximum speed? The aim of the paper is to find the answer to this question. In addition, generated random numbers should not leave a cryptographic system, because according to the Kerckhoffs thesis, the security of the whole system should be based only on a key. The cryptographic system should be enclosed within a single chip. In order to check new ideas and prove them, there were used NIST 800-22 test suite and restarts mechanism. The basic concept of the generator built of ring oscillators is still the same; ring oscillators are combined by XOR gates tree. A single ring oscillator consists of inverter, latch and NAND. This kind of construction provides a tool to make synchronous start and stop of all oscillators and the restart mechanism technique is applied in this manner. The speed of generation was increased by using multiple parallel generator trees to generate instantly the whole n-bit word. The paper shows that reproduction of the base structure is not a simple method of increasing the speed of generator. Moreover, it is always important to carefully consider all new ideas, because even if the NIST statistical test suite is passed, there is a chance that the restart mechanism will show some correlations that can be used during attack on the system.