Seagate Barracuda 7200.9
Access Time and Transfer RateFor diagnostic purposes only, StorageReview measures the following low-level parameters: Average Read Access Time- An average of 25,000 random read accesses of a single sector each conducted through IPEAK SPT's AnalyzeDisk suite. The high sample size permits a much more accurate reading than most typical benchmarks deliver and provides an excellent figure with which one may contrast the claimed access time (claimed seek time + the drive spindle speed's average rotational latency) provided by manufacturers. Average Write Access Time- An average of 25,000 random write accesses of a single sector each conducted through IPEAK SPT's AnalyzeDisk suite. The high sample size permits a much more accurate reading than most typical benchmarks deliver. Due to differences in read and write head technology, seeks involving writes generally take more time than read accesses. |
WB99 Disk/Read Transfer Rate - Begin- The sequential transfer rate attained by the outermost zones in the hard disk. The figure typically represents the highest sustained transfer rate a drive delivers.
WB99 Disk/Read Transfer Rate - End- The sequential transfer rate attained by the innermost zones in the hard disk. The figure typically represents the lowest sustained transfer rate a drive delivers.
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With a 13.7 millisecond access time, the Barracuda 7200.9 posts virtually the same mark as its predecessor. Subtracting the requisite 4.2 ms to account for rotational latency nets a measured seek time of 9.5 milliseconds. Seagate specs the 7200.9 at a rather conservative 11 ms, so the drive's measured score easily arrives well under the firm's claim. Unlike the 7200.8, the newest Barracuda delivers a relatively reasonable average write access time of 14.9 milliseconds. Though still on the high side when compared with most of the competition, it is a great improvement over the 7200.8's 23.3 ms score.
At 125 GB/platter versus the 7200.8's 133 GB/platter, the 7200.9 takes a slight step back in areal density. As a result, the newer drive suffers a bit when it comes to sequential transfer rates. Outer-zone measurements weigh in at 62.0 MB/sec, a full 10 MB/sec lower than the record-setting 7200.8. Even more telling, the 7200.9's maximum score also falls below 100 GB/platter units such as the MaXLine and Caviar RE2. As data moves inwards, scores decay down to a low of 34.4 MB/sec and best only Hitachi's 80 GB/platter Deskstar. It appears Seagate chose quite a conservative zoning pattern in moving the Barracuda line back to a four-disc assembly.
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Some Perspective It is important to remember that seek time and transfer rate measurements are mostly diagnostic in nature and not really measurements of "performance" per se. Assessing these two specs is quite similar to running a processor "benchmark" that confirms "yes, this processor really runs at 2.4 GHz and really does feature a 400 MHz FSB." Many additional factors combine to yield aggregate high-level hard disk performance above and beyond these two easily measured yet largely irrelevant metrics. In the end, drives, like all other PC components, should be evaluated via application-level performance. Over the next few pages, this is exactly what we will do. Read on! |