During sequential writing the HDDs with different firmware show different results. And again we witness barracuda 7200.7 Serial ATA being strictly individual: its graph is absolutely unlike the other ones. It boasts better performance with the data blocks over 8KB and with smaller data blocks the leadership belongs to Barracuda Serial ATA V. The red color now indicates the results for firmware version 3.04: they are considerably lower than they are supposed to be. The firmware version 3.06 and 3.54 is already free from this bug.
The maximum performance of Barracuda 7200.7 is more than 30% higher than Barracuda ATA V, which totally corresponds to the data density increase. However, if we look into the specs list, we will see a very strange thing there. The claimed bit density has become only 9% higher according to the specs, and the remaining increase in the storage capacity has been achieved only due to higher per track density! The data in the specs is definitely wrong. By the way, all this reminded me of the times of Barracuda ATA III, it was also much faster than the previous generation models in “raw” read/write speeds.
Now let’s compare the average access times. The reading and writing are performed in 8KB blocks with random addresses (these are the particular cases for the DataBase pattern).
What do we see here? And we see a TENDENCY. The average access time demonstrated by the hard disk drives is directly dependent on their “coolness”. The cheapest models show the worst access time, the 8MB buffer helps improve the situation a little bit, but Barracuda 7200.7 Serial ATA drives simply work wonders here! Their access time appeared better than that of the previous generation model with “cut-down” platters (you can read more about the influence of this “cut-down” design in our article called Maxtor DiamondMax Plus 8 HDD Family Review. Part I). The difference between ATA and SerialATA Barracuda 7200.7 makes about 2ms, which is more than 15%!
I was trying real hard to find a reasonable explanation to this fact. As you probably remember, we have already investigated a similar phenomenon by Western Digital drives and arrived at a very interesting conclusion (read our article called Western Digital WD2500JB HDD: More than Drivezilla?!). However, the surface graphs of the today’s testing participants are very similar and the differences lie within the allowed measuring error. Tat is why the assumptions about varying amount of servomarks (to be more exact, sector indicators aka Sid) or different spindle rotation speed do not count. There appear to be not too many variants left:
- Barracuda 7200.7 has no options for acoustics management (AAM) that is why we don’t know if the drives work in quiet or fast mode. For more expensive Serial ATA modifications intended for serious workstations Seagate might enable fast seek, and for mainstream models – quiet seek.
- For SerialATA Barracuda 7200.7 hard disk drives a more powerful actuator might be used for the above described reasons.
- firmware algorithms may affect the average access time. Although 2ms is a way too much…