Western Digital Raptor® X WD1500AHFD 150 GB SATA Hard Drive (Retail Version)

Raptors may have been extinct for millions of years but their latest resurrection by Western Digital certainly caused a minor uproar. Not for ethical reasons but for bringing 10k performance to the ATA desktop crowd (SATA as it may be). However, time goes on and many may have grown out of the maximum 74 GByte the original Raptor offered. Beyond the raw rotational speed, the cache and SATA technology started to look a little dated. Just as the Barracuda seems to have dulled the Raptor's bite, the larger and improved model is back to show that its teeth are still a force to be reckoned with. But enough of the puns and lets see how the WD Raptor X (150 GByte) stacks up ...


IN A NUTSHELL

The Raptor 150 GByte comes in a "plain" version and the beautiful "X" version. The difference between the two is simply the clear window in the Raptor X that allows to watch the upper head at work. For about $30 - $50 less you get a technically identical drive without the cool window. You decide what it's worth to you since under normal use it's likely to be hidden inside a case anyway.

The WD1500AHFD (Raptor X) demonstrates nicely why 10k drives are not mainstream (yet?). It's pricey and for most home users out of reach. Beyond that, there is also a lot to love about it. NCQ (native command queuing) finally found its way into the Raptor line and combined with 16 MByte cache it's clearly an attempt to further elevate the raw spindle speed. It does so successfully and no other drive in the SATA arena can match the performance. In fact, most 7200 rpm drives have a hard time to keep up with a single Raptor X even when doubled up in a RAID 0 configuration (striping).

The higher density of the 150 GByte version gives it a clear advantage even over the 74 GB Raptor, but that's also due to the larger cache and especially the NCQ, which is most important for normal office applications where small file inefficiencies matter. The SATA/150 interface may not sound impressive but even two drives in RAID 0 are still (barely) within the SATA bus speed of 150 MBps. The only exception is the burst rate which doesn't bare much practical use in most applications or games anyway.


PERFORMANCE

The original Raptors relied on pure spindle speed and relatively low density to pull off record speeds with acceptable reliability. The new drive isn't a giant either but density goes up and so does the speed. Combined with NCQ the specs suggest that this should be the desktop drive to beat in 2006 (other than the pricey 10k or 15k SCSI drives).

Sandra2005: Drive Index [MB/s]
- WD Raptor X 150 = 72
- WD Raptor 74 = 58
- Seagate 7200.10 (320GB) = 63
- Seagate 7200.7 (80GB) = 51

HD Tach 3: Sequential Read
- WD Raptor X (150) = 59 MB/s ... 90 MB/s (inside ... outside), AVG 78 MB/s
- WD Raptor 74: 52 MB/s ... 73 MB/s (inside ... outside), AVG 65 MB/s
- Barracuda 7200.10 = 40 MB/s ... 80 MB/s (inside ... outside), AVG 63.5 MB/s

Interpretation: The Raptor X (150 GByte) is the expected winner in both raw speed and overall performance. The addition of NCQ helps the Sandra index significantly while pure spindle speed is quite visible in the minimum (inside) speed of a whopping 59 MByte/sec read speed. There is no doubt that the Raptor X profits from a combination of NCQ, 10,000 rpm and higher data density. It's the leader of the pack for desktop hard drives. Combine two Raptor X in a RAID 0 and numbers get close to the theoretical bus speed limit with 146 MB/s and the average of 129 MB/s is not bad either.



DETAILS

Versions: WD doesn't make it easy to distinguish, and after reviewing the specs it appears that both versions of the 150 GByte Raptor are identical in their tecnology (cache, speed, ncq, sata). So the only difference is the clear window in the Raptor X. While this is definately cool, it's not essential.

Cost: [***--] It's expensive, there is no doubt about that. If on a budget, none of the Raptors is for you ... and especially the nearly $300 for the 150 GByte Raptor X (best offer) is no pocket change. That makes about $2 per GByte! The Raptor X is roughly three times the cost of Seagate's 320 GByte 7200.10 despite half the capacity. Further, real life benefits may only be justified for enthusiasts. Others may be better off with Seagate's 7200.10 series ($0.32 / GByte).

Reliability: [*****] Basically every recent hard drive on the market is S.M.A.R.T. compatible -- a drive condition monitoring feature provided by most BIOS in modern motherboards. Useful as it is, it often is required to enable it manually for an installed hard drive (in the BIOS). WD even added the 5-year warranty we're used to from Seagate drives. Beyond that, RAFF (see below) adds stability in situations where multiple drives may cause vibration interferences. (My other Raptors seem to do just fine in rubber mounts despite having 4 in one rack.) While you should not be putting to much faith into a manufacturer rating like the 1,200,000 hours MTBF (or 136 years mean time before failure), it's still an indication that WD is confident the Raptor is reliable. (So far, all mine certainly seem to confirm that.)

SATA (150): [****-] Unrealistic Burst speed aside, SATA/150 is still no bottleneck for single hard drives and seldom for two drives either -- even in the case of the Raptor X in RAID-0 configuration. Depending on your controller, even a RAID 0+1 (striping and mirroring) may not require more than standard SATA drives ... if your controller supports 3 Gbps divided into two 1.5 Gbps streams. In that case the striping (RAID 0) could be on one stream and the mirror (RAID 1) could be on another, and both would still run on maximum speed. Enthusiasts might still moan that the Raptor X is not SATA-II (300) capable, but in reality that's more for bragging rights than true performance reasons.

Noise: [****-] Seagate's SoftSonic motor impressed with its "whisper-quiet" operation, which none of the Raptors can match. However, put the Raptor X on rubber mounts and it turns out to be a little quieter that the Raptor 74 and overall quite alright for a 10k drive.

10,000 RPM: [*****] Sustained transfer speed (large files) heavily depends on spindle speed and the Raptor X packs increased data density for new performance heights of any ATA drive. Western Digital has a reputation of fighting with reliability issues, but frankly none of my current Raptor 74 had any problems in the recent year and from my experience they're basically on par with the Maxtors I owned and the (supposedly more reliable) Seagates I currently own. Despite the higher rpm, the Raptor X uses about the same power as most drives (10 Watts) and heat is moderate as well. With the Raptor X Western Digital introduced a new feature called "Rotary Acceleration Feed Forward" (RAFF), which aims for improvements in vibration-prone multi-drive systems.

NCQ: [*****] The previous Raptor offered raw speed but in most applications the task management of Native Data Queuing (NCQ) has become the norm only in Seagate's SATA desktop drives. In conjunction with the large cache, the Raptor X now caught up and performance benchmarks show that it's a good implementation. With NCQ the reading head travels less if data within the sequence is closer. The actual order of the data is restored upon transmitting it back to the CPU. The effect is naturally limited in less predictable situations or simply too large chunks of instructions and data.

16 MB Cache: [****-] Another big jump from the Raptor 74 is the (much) larger cache to store pre-fetched data and access without moving the heads. Other than supporting NCQ better, this has typically has no effect on operations like recording video due to the large files which virtually bypass the buffer.

© 2006, theuerkorn


LINKS

- Seagate Barracuda 7200.7 - 80 GByte hard drive
- Seagate Barracuda 7200.10 - 320 GByte hard drive
- Western Digital Raptor - 74 GByte hard drive