Performance difference in unwrapkey based on the type of wrapped key in HSM

I'd like to know why there is a performance difference depending on which key HSM unwrapkey is performed on. In the case of having two HSMs, when I perform unwrap using a key generated with CKK_RSA, I can achieve a processing rate of around 500 per second. However, when I perform unwrap using a key generated with CKK_EC, the processing rate is only about 80 per second. I'm curious about the reasons behind this performance difference. Why is unwrapping a key generated with CKK_EC slower? Is this speed difference expected?