Now let’s compare the performance of different SCSI controllers (Adaptec 39320D was tested with two different driver versions):
As you see, Fujitsu MAS3735NP hard disk drive appeared a little faster when working with U160 Adaptec 29160N controller than with the U320 controller. Moreover, driver 1.1 for Adaptec 39320D controller turned out slower than driver 1.0.
Now let’s increase the workload:
And we see that the performance difference between different controllers/driver versions grew even more evident. The maximum performance is again obtained with the Adaptec 29160N controller, and the worst results are shown by our HDD with Adaptec 39320 with driver version 1.1.
Further workload increase makes this parity even more stable.
Fujitsu MAS3735NP achieves the maximum performance with the U160 controller. Does this mean that U160 interface is “faster” than U320? Well, if we evaluate the interface speed according to the performance of a single HDD, then yes, U160 is faster. However, as you see, a lot depends not only on the maximum interface bandwidth but also on the quality of algorithms used in the controller driver (we are not going to go into details regarding the “compatibility” of the drivers and HDD firmware here).
Now let’s pass over to Sequential Reading and Writing.