A storage system allocates single-level cell (SLC) blocks in its memory to act as a write buffer and/or a read buffer. When the storage system uses the SLC blocks as a read buffer, the storage system reads data from multi-level cell (MLC) blocks in the memory and stores the data in the read buffer prior to receiving a read command from a host for the data. When the storage system uses the SLC blocks as a write buffer, the storage system retains certain data in the write buffer while other data is flushed from the write buffer to MLC blocks in the memory.