The key factors of the computer system that affect performance are:

• The chip architecture: how fast the processors are, how many and what kinds of operations can be done simultaneously, and how fast the various operations are
• The memory hierarchy: how many pieces of data can fit into the memory with the fastest access, and how long it takes to retrieve data from slower parts of memory
• The I/O configuration: where files are stored and how quickly they can be accessed
• The connection between nodes, e.g. the Giganet high-performance switch
• What kinds of optimization the compiler can perform