Patent ID: 8145828

Claim:
A storage apparatus, comprising: a plurality of packages each including plural flash memories and a flash memory control unit controlling the plural flash memories; and a storage unit storing information of power supply capacity, and wherein a first parallel-processable number of flash memories that can be processed in parallel in the entire storage apparatus performing writing, erasing or reading in parallel is determined based on the stored information of power supply capacity, wherein, when the flash memories to be access targets of a received write command or a read command to the packages exceed the first parallel-processable number, a second parallel-processable number of flash memories that can be processed in parallel in each package is calculated, wherein the second parallel-processable number is issued with the write command or the read command, wherein the flash memory control unit of a package which received the second parallel-processable number makes any of the plural flash memories wait for the timing of transfer of a write operation start command, read transfer or transfer of an erase command to control so that the flash memories not exceeding the second parallel-processable number operate in parallel, and wherein the second parallel-processable number is calculated on the basis of the first parallel-processable number so that a ratio between the number of flash memories accessed in each package and the number of parallel-processable flash memories of each package is the same as a ratio between the number of flash memories accessed in the storage apparatus and the number of parallel-processable flash memories of the storage apparatus.