Storage system and operation method thereof

A method of operating a storage system comprising a memory control circuit, a first type memory, and a second type memory, a first read latency of the first type memory being shorter than a second read latency of the second type memory, the operating method including:

• in response that a first data is written into the storage system, the memory control circuit dividing the first data into a first part and a second part;
• the memory control circuit writing the first part of the first data to the first type memory;
• and
• the memory control circuit writing the second part of the first data to the second type memory,
• wherein, a data amount of the first part of the first data is related to a data transfer rate of the second type memory and a read latency difference,
• the read latency difference is related to the first read latency of the first type memory and the second read latency of the second type memory.