Western Digital Raptor

In 2003, Western Digital released the first incarnation of the Raptor series: the WD360GD.[7] It featured a capacity of 37 GB on a single platter, a Serial ATA interface, and was the first ATA drive to operate at a spindle speed of 10,000 rpm. Like many early SATA drives, the Raptor was not a "real" SATA drive because it was really a PATA drive that used an 88i8030C interface bridge chip from Marvell. However, this fact did not significantly hamper the Raptor's performance. WD360GD Raptors do not use the 3.3 V Serial ATA power line. There is no need to use a SATA power connector as it will not be fully utilized.[8]

As is usually the case for hard drives featuring a faster spindle speed, the Raptor outperformed other ATA drives and in some situations was even able to reach the performance of contemporary 10,000 rpm SCSI drives. SCSI drives still outperformed the Raptor in multi-user scenarios, but for high-end home computers it fared very well. For enthusiasts' systems, the Raptor also had the key advantages of low noise and temperature levels compared to similarly performing drives.

All WD360GD drives with Part Number WD360GD-00FNA0 (December 2003) and earlier cannot accept SATA latch cables, as the SATA data connector does not have the required rails. Therefore, only normal cables can be plugged into these connectors.

WD360GD Raptors with the Marvell 88i8030-TBC PATA to SATA bridge chip, such as WD360GD-00FNA0 (December 2003) and earlier, are limited to UDMA 5 transfers. In Linux, "applying bridge limits" is displayed and then it allows transfers up to UDMA/100. In Microsoft Windows, they are reported as UDMA 6, but give a burst rate of 104 MB/s, while WD360GD with the 88i8030-TBC1 chip are reported as UDMA 6 and give a burst rate of 122 MB/s, close their theoretical limit of UDMA 6. Those Raptors limited at UDMA 5 were bought for SATA I 150 MB/s support, but they only support the legacy PATA UDMA 5 at 100 MB/s.

Like its larger brother the WD740GD, the WD360GD was revised in 2006 and released with the designation WD360ADFD - incorporating twice as much on-board cache (16 MB vs 8 MB), at least one side of a single platter that offers twice the areal density, and enabling NCQ.

Western Digital WD740

The second generation Raptor was introduced in early 2004, featuring two platters for 74 GB of storage space. Unlike its predecessor, the WD740GD didn't use ball bearings to support the spinning disks, but rather used fluid dynamic bearings. These allowed the new Raptor to operate at a noise level comparable to the quieter 7,200 rpm drives.

Another advantage the WD740GD had over its predecessor was Tagged Command Queuing, a feature that had previously been available only in SCSI drives. Command queuing resulted in a notable increase in the WD740GD's multi-user performance—a key discipline where its predecessor failed compared to SCSI drives. However, enabling command queuing on the WD740GD resulted in a performance decrease in single-user scenarios. It is worth noting that as of 2005, only a few SATA controllers could fully support command queuing. This drive became immensely popular in high-end gaming systems because of these features.

In 2006 Western Digital revised the WD740GD specification and released the WD740ADFD, ostensibly the same drive but with 16 MB of on-board cache, and a larger single platter (one 75 GB platter vs two 37 GB platters). Support for TCQ (rarely supported on SATA RAID controllers) was dropped in favor of NCQ, and at the same time replacing the SATA-to-PATA bridge controller chip with a native SATA controller. Unfortunately one of the major enhancements of WD740ADFD, the NCQ, is implemented so badly in the WD740ADFD-00NLR1 that it has been added to the Linux libata drive blacklist. The WD740GD did not apply because it uses TCQ and not NCQ. In order to deal with it, NCQ is disabled Link to the NCQ-Bug in the Kernel Bug Tracker. In TCQ capable controllers, the WD740GD is possibly faster than its successor as some of the WD740ADFDs' gains are lost. The WD740ADFD has also caused problems in some motherboards and their manufacturers had to release BIOS updates.

The third generation Raptor was released by Western Digital in January 2006. It features two 75 GB platters (for a total of 150 GB) and a more advanced system of Native Command Queuing. At the same time, the Raptor X was released. It has identical specifications to the standard Raptor,[9] but it has the addition of a clear polycarbonate window in the drive cover, making the movements of the disks and magnetic heads visible. This unique feature is likely to be popular with case modders. Like the regular Raptor, the Raptor X has a MTBF rating of 1.2 million hours, or 137 years. Both drives are covered by a five-year warranty. While this drive uses the NCQ feature of SATA 2, it lacks support for the increased bandwidth of SATA 2.[10]

An early-edition GLFS model

The fourth-generation Raptor was announced by Western Digital in April 2008. The new drive is being sold under the VelociRaptor name.[11] As well as increasing the capacity to 300 GB (split over two 150 GB platters), the form factor is as follows:

• GLFS models - 2.5-inch drive in a 3.5-inch IcePack frame (serving as a heatsink)
• HLFS models - 2.5-inch drive in a redesigned 3.5-inch IcePack with proper SATA connector position (see below)
• BLFS models - 2.5-inch bare drives (incompatible with notebooks)

Earlier GLFS models have been criticised for being incompatible with 3.5-inch SATA hot swap bays due to the position of the connectors; however, a new revision (HLFS models) has been released which remedies this problem.[12] Furthermore, TLER has been enabled by default on HLFS models.

Western Digital later released a 2.5-inch Velociraptor (BLFS models) which is nearly identical to the 3.5-inch version, but without the IcePack heat sink. These drives are designed for use in servers and are unsuitable for laptops because of their power requirements and 15 mm thickness. TLER is also enabled by default on BLFS models.

A severe issue with the fourth generation of raptor drives was faulty firmware, which caused the drive to report TLER timeouts after roughly 50 days of continuous operation (precisely 49.71 days counted in milliseconds, which corresponds to the overflow of a 32-bit number).[13][14][15] The bug has been present in all models of drives shipped, from their introduction up to late 2009. WDC never admitted the existence of this bug, or officially released a firmware update; however, an update was leaked by a WDC technician and is still readily available through various download sites.[16] The bug was of minor significance for desktop users, but prolonged drive operation in RAID setups could result in mass drive dropouts after 49.71 days, causing maintenance problems and potentially data loss.

The fifth-generation Raptor (or second-generation VelociRaptor) drive was announced in April 2010. Besides increasing the total capacity to 600 GB, the SATA interface speed had been increased to 6 Gbit/s. The drives are sold either in the same IcePack mounting frame as the previous generation, or as bare drives (intended for rackmount servers). While the drive width of 2.5 inches may entice users to try to install a VelociRaptor drive in a laptop, this is not possible. Not only are the drives a thicker-than-usual 15 mm high, but they require both +12 V and +5 V power that most laptops cannot provide. Standard laptop hard drives typically only require +5 V.

Two third-generation (VR333M) 1 TB VelociRaptors in IcePack mounting frames

The sixth-generation Raptor (or third-generation VelociRaptor) was announced by Western Digital in April 2012. The drives are 2.5-inch devices with 15 mm in height, sold either as bare drives (CHTZ and BHTZ models) or mounted in the IcePack 3.5-inch mounting frame (DHTZ and HHTZ models), which continues the variants available in the previous generation. Beside increasing the capacity to 1000 GB, the buffer size has been doubled to 64 MB. They are also the first Raptor models employing the Advanced Format (AF) 512e internal layout.[17][18]