Western Digital Raptor Preview: 10,000RPM & Serial ATA

Access Time & Transfer Rates

Although the focus of this review is entirely on real-world performance numbers, we felt the need to start out with Access Time and Transfer Rate tests to illustrate some basic differences between the drives being compared here today.

The two purple bars are the two 10,000RPM SCSI drives in this comparison, blue is for all of the ATA/SATA drives and red is for the new comer WD Raptor.

We measured the access time of the drives by conducting 25,000 randomly distributed read requests, the average service time for those requests is reported below:

Access Time Comparison Average Read Access Time in ms (lower is better) Maxtor Atlas 10K IV (36GB U320 SCSI) Seagate Cheetah 10K.6 (36.7GB U320 SCSI) Western Digital Raptor WD360 (36.7GB SATA) IBM Deskstar 180GXP (185.2GB PATA) Maxtor DiamondMax Plus 9 (80GB PATA) Seagate Barracuda Serial ATA V (80GB SATA) Western Digital Caviar WD1200JB (120GB PATA) Seagate Barracuda ATA V (120GB PATA) 7.4 8.0 8.4 12.8 12.9 13.0 13.7 13.9 | 0 | 3 | 6 | 8 | 11 | 14 | 17

Here we see the benefits of a 10,000 RPM spindle speed, although not quite as fast as the two SCSI drives, the Raptor does boast a significant advantage over any of the 7200 RPM PATA/SATA drives.

Sequential Transfer Rate Beginning Transfer Rate in MB/s (Higher is better) Maxtor Atlas 10K IV (36GB U320 SCSI) Seagate Cheetah 10K.6 (36.7GB U320 SCSI) Western Digital Raptor WD360 (36.7GB SATA) IBM Deskstar 180GXP (185.2GB PATA) Maxtor DiamondMax Plus 9 (80GB PATA) Western Digital Caviar WD1200JB (120GB PATA) Seagate Barracuda Serial ATA V (80GB SATA) Seagate Barracuda ATA V (120GB PATA) 70.4 68.7 57.6 56.2 50.3 49.3 44.1 43.4 | 0 | 14 | 28 | 42 | 56 | 70 | 8

At the start of the platters the transfer rate is at its highest potential, and thus we see some fairly impressive numbers from all of the drives here. It's interesting to note that the Raptor can only offer a 2% performance advantage in sequential transfer rate over the PATA IBM Deskstar 180GXP.

Sequential Transfer Rate End Transfer Rate in MB/s (Higher is better) Maxtor Atlas 10K IV (36GB U320 SCSI) Seagate Cheetah 10K.6 (36.7GB U320 SCSI) Western Digital Raptor WD360 (36.7GB SATA) Maxtor DiamondMax Plus 9 (80GB PATA) IBM Deskstar 180GXP (185.2GB PATA) Seagate Barracuda Serial ATA V (80GB SATA) Western Digital Caviar WD1200JB (120GB PATA) Seagate Barracuda ATA V (120GB PATA) 43.8 40.2 37.6 33.2 30.9 30.1 29.2 24.8 | 0 | 9 | 18 | 26 | 35 | 44 | 53

The Raptor fares much better once we reach the end of its capacity, although it still falls noticeably behind the two SCSI contenders.