•Memory-processor bandwidth
–performance depends completely on keeping the vector
registers supplied with operands
from memory
•Size of main memory and extended memory
–bandwidth of main memory is much higher but main memory
is more expensive
–size determines -- size of problem that can be run
•scalar registers/scalar processors for scalar instructions
•I/O through special processor - -
–T90 can produce data at 14400 MB/sec -- Disk 20MB/s.
Thus single word can take
720 cycles on Cray T90 !!