Performance in Intel IOMeter SequentialRead and Write Patterns
During the SequentialRead and Write test we check how well the hard disk drive can cope with ordered requests featuring linearly growing address. The requests queue depth in this case remains equal to 4, and once per minute the size of the requested data block changes.
The SequentialRead graph is an excellent piece of evidence confirming the specifications claimed by the manufacturer. You can clearly see from this graph that the curve standing for USB 2.0 interface crawls up until the data block size reaches 64KB. Then it turns into a horizontal line indicating that the HDD performance is limited by the interface bandwidth. As we have already said the manufacturer claimed it to be 34MB/s for USB 2.0 interface.
The same thing is true for FireWire interface. The HDD ran fastest of all when the data block size is 1MB, having reached the claimed maximum of 40MB/s. Again, both IEEE 1394 controllers run equally fast.
During SequentialWrite tests the HDD runs slower, than during erading, as we have actually expected. Again USB 2.0 looks less attractive. The write speed when the HDD work via this interface reaches the promised maximum, which is slightly above 26MB/s, with the 64KB data block (you can see a corresponding graph running horizontally at a certain point). With FireWire interface, the hard disk drive performs more impressively. Here we can already notice the performance difference between configurations with different controllers involved. You can already see it in case of 4KB data blocks and up. The HDD shows better write speed when it is used with Agere FW323 controller, which reaches almost 2MB/s.