External Disk Storage System Marketplace Trends Page 2
Two factors identified by IDC as disruptive technologies are ATA-based subsystems and iSCSI. As the data transfer rate of ATA has grown, its usage has transitioned from the desktop to workstations and entry-level servers. As a result, ATA is regaining market share from SCSI is several market categories.
"More and more, we are seeing ATA taking over from SCSI in the enterprise marketplace," says McArthur. "There appears to be greater usage of slower ATA and Serial ATA (SATA) drives for various uses due to its low cost and high capacity. SCSI on the other hand tends to be faster, more expensive, but more reliable".
SCSI data rates, too, have been steadily increasing over the past few years. Thus SCSI has also evolved — from desktop drives in its early days to mid-range and high-end storage/server systems. The latest revision to the SCSI standard, Ultra320 SCSI, doubles the maximum data transfer rate for the SCSI bus from 160MB/sec to 320MB/sec.
McArthur believes a market dichotomy is emerging: Fibre Channel (FC) SCSI and Serial-Attached SCSI (SAS) drives, operating at 15,000 rpm, at the top of the disk hierarchy. They will become the norm for high performance applications and business processing.
ATA and SATA drives running at around 7,200 rpm will be the norm at the lower end. They will be used mainly for email, file, and print servers and low-end storage.
Eventually, IDC sees the market share of SCSI falling from its high of over 90 percent in 1998 to a little over 30 percent by 2006. SATA and FC, on the other hand, will gain ground. FC will grow to over 10 percent of the enterprise storage market, primarily for use in high-end SANs. SATA will probably surpass SCSI by 2006 with over 40 percent of the total.
"SCSI will become focused on mid- to high-end servers and networked storage," says McArthur. "SATA's focus will remain on entry servers, fixed content, and as a supplement for tape backup."
McArthur sees this shift as an opportunity for the emerging iSCSI technology, which will gain ground especially in new areas such as upgraded storage for old data that resides on microfiche.
Feature courtesy of Enterprise IT Planet.