X-bit labs

WD740GD aka Raptor 2 Hard Disk Drive Review (page 13)

Category: Storage

by Nikita Nikolaichev

[ 02/18/2004 | 11:37 PM ]

Performance in FC-Test

Now we are going to try our HDDs in the last benchmark intended to check how fast they write, read and copy files. This is going to be the first time we use FC-test for a massive SCSI HDDs testing. And to tell the truth, we were really surprised with the results, I should say.

The results for WD drives were obtained with a Promise S150 TX2+ controller:

This is a very illustrative diagram, isn’t it? The write speed appeared very low for SCSI drives. Could it be the driver of our Adaptec controller? Or maybe it is the peculiarity of the SCSI solutions, because all caching algorithms are set for random workload and not for streaming requests. It is especially true for lazy writing… Anyway, last time we tested a Fujitsu SCSI drive, it demonstrated normal write speed (see our article called WD Raptor: First ATA Hard Disk Drive with 10,000rpm Speed for details).

And SATA drives from Western Digital on the contrary, performed brilliantly: the average write speed for files from the ISO pattern exceeded 40MB/sec. So, it is not at all surprising that WD740GD was faster than WD360GD on all patterns.

Now let’s compare the read speed:

Suring files reading SCSI HDDs managed to regain their reputation: only in the ISO pattern WD740GD managed to outpace SCSI drives from Seagate. At the same time the Hitachi drive, which boasts much faster linear read speed than WD740GD, fell just a little bit behind the WD solution in all patterns. Could it be that SCSI drives have something to help them during reading? Especially, when the workload is a little bit higher than the linear one…

Among the two WD drives, the newcomer is a definite leader.

Now let’s check file copying:

And what happens during files copying? Some data is read from the HDD and written into a different location. In other words, every copy operation can be split into four simple commands: read the data, move the heads, write the data, move the heads.

The results of our SCSI solutions show very clearly that the data writing is their bottleneck in this entire process, while the remaining three steps are performed at almost no expense at all.

WD drives appeared somewhat faster than SCSI drives during files copying. SCSI HDDs failed mostly on the ISO pattern, while WD740GD showed its real best there.

During file copy from one partition to another, it takes more to move the heads and the overall performance gets somewhat lower. However, it hardly changes anything: SCSI drives are defeated by their SATA rivals from Western Digital.