On chip encryption Nitrokey HSM 2

I would like to know if the encryption (symetric and asymmetric encryption) is computed by the chip (smartcard-hsm) or by the host computer because of the processing power ?

Yes, all cryptographic operations are performed in the SmartMX2 security controller of the SmartCard-HSM.

For performance figures related to asymmetric operations please refer to the datasheet.

For AES-128 with a block length of 1216 (max APDU) you can assume 300ms per block, including transmission into the device, crypto operation and transmission back.