Hard-drive performance is at an all-time high, yet they’re still the most critical bottlenecks for system performance. However, some notable improvements may be changing the scene.
When it comes to computers, what we really care about is performance, isn’t it? We want the fastest processor, the most powerful video card, the speediest hard drive on the block. Sure, reliability is important, too, but speed is king.
As we discussed last month, Intel’s fastest processor is currently the rip-roaring Pentium 4 3.2-GHz CPU with 800-MHz FSB. Meanwhile, AMD is touting its top-of-the-line Athlon XP 3200+ riding a 400-MHz bus. And we scrutinized video cards prior to that. However, the hot frontrunners from several months back have now been relegated to second tier. New graphic heavyweights include ATI’s Radeon 9800 Pro 256MB and NVIDIA’s GeForce FX 5900 Ultra. Unfortunately, the problem with living on the bleeding edge is that it’s always bleeding.
The time has arrived to examine the platter. Specifically, are hard drives getting faster? Simply put — yes. Hard-drive performance is at an all-time high. Nevertheless, if we ask if there’s been a significant increase in hard-drive performance during the past 12 months, the honest answer is — not really. Hard drives are currently one of the most critical bottlenecks for system performance. While storage capacity has increased remarkably, data-transfer rates have not kept equal pace.
In essence, two notable improvements in hard-drive performance have arrived in recent months. The more significant development in performance and design is that of Serial ATA (SATA). It’s the implementation of the near-future in PC storage. Second is the release of Western Digital’s Raptor, the first non-SCSI drive to spin to the tune of 10,000 RPM. Unfortunately, this SATA drive’s “limited” 36-GB capacity and server-optimized design make it unfit for general desktop use. It does, though, harken of things to come.
Until earlier this year, the choice in hard drives was basically IDE or SCSI. The latter has traditionally offered better performance, but not apart from its inherent shortcomings. SCSI drives carry the baggage of greater noise, heat, and vibration levels. Obviously, these drawbacks make them unacceptable for general consumer applications. IDE drives (known now as Parallel ATA due to the advent of SATA) offer reduced performance compared to SCSI but are by far the more user-friendly and affordable alternative.
Serial ATA hard drives, however, have arrived offering consumer-level storage with several advantages over Parallel ATA (PATA) drives — primarily speed and simplicity. What exactly is Serial ATA? While PATA employs parallel-based technology to transfer data, SATA serves up its data flow via serial signaling. Rather than utilizing a bulky 40-wire ribbon cable along parallel routes like PATA, Serial ATA employs a much smaller, more flexible, and potentially longer seven-wire cable (up to three feet in length). It’s also 100 percent software-compatible with existing Parallel ATA technology.
What precisely are the benefits of SATA and when will they be realized? Naturally, Serial ATA is faster than PATA, but only incrementally so at this juncture. Present SATA drives boast transfer rates of 150 MB per second. That’s only a smidgen more than PATA rates of 100 MB and 133 MB per second. Accordingly, today’s SATA drives only exhibit a performance improvement over PATA drives in the neighborhood of approximately 12 percent under ideal conditions. That’s not a significant boost.
Moreover, speed improvements don’t seem to be consistent from one drive manufacturer to another. For instance, when comparing Seagate Barracuda V SATA and PATA drives, the performance differential is near non-existent to that exhibited between PATA and SATA versions of Maxtor’s DiamondMax Plus 9. Specs for both manufacturers are similar and both drive models sport 8-MB caches. Apparently, Maxtor has an edge in its current SATA drive design that enables a greater performance boost than the competition.
While we’re talking about 8-MB hard-drive caches, it’s important to know that a drive with an 8-MB cache will perform approximately 5 percent better than one with just a 2-MB cache. So cache is just as important as any other factor in overall drive performance.
Still, current SATA standards are not the whole story. In 2004, Serial ATA II will arrive offering a bandwidth increase to 300 MB per second, followed in 2007 by Serial ATA III which will bump performance to 600 MB per second. Of course, more advanced hard drives will be required to take advantage of the available increase in bandwidth when it arrives.
Today, the majority of SATA’s advancements are more practical in nature than performance-oriented. The move to a thinner and more flexible cable in place of cumbersome IDE ribbon cables aids in hard-drive placement and cable routing while offering improved airflow. Smaller cables also mean smaller connectors, freeing up space on motherboards for more compact designs (especially attractive in small-form-factor computers). Gone, as well, is the need to set jumpers. Serial ATA is point-to-point with just one device per channel. There are no master-slave relationships with which to contend.
Another positive aspect of the move to SATA is that it allows for platform cost reductions. We’re not seeing that yet, but once the volume of SATA-based hard drives increases, approaching that of PATA units, the benefits will begin to kick in. Plus, lower voltages required for Serial ATA will assist in alleviating current design constraints.
So what are the downsides to Serial ATA? Since serial technology can only “speak” to one device per channel, twice as many connectors are required in motherboard design over PATA. Still, with a much smaller footprint, it should be no problem to provide sufficient SATA connectors for most if not all PC applications.
Also, throughput is currently limited by implementations requiring a controller card on the PCI bus, a technology with a theoretical maximum transfer speed of 132 MB per second. However, integrated chipsets such as Intel’s new ICH5 will serve to remedy this weakness. Additionally, SATA drives are more expensive at this juncture, retailing for about 25 to 30 percent more than their Parallel ATA alternatives. Regardless, SATA’s plusses far outweigh its minuses.
While Serial ATA is the interface specification for next-generation computing platforms, it’s currently limited to hard drives. Eventually, this technology will be employed to connect optical drives as well. Unfortunately, Parallel ATA won’t vanish any time soon. Since DVD and CD makers view SATA as more of a luxury than a necessity (the extra bandwidth is not currently required), the transition for these devices will occur much more slowly.
In the end, SATA is an evolutionary as opposed to revolutionary technology. Nevertheless, it is one with the potential to become ground-breaking over the next few years. We’re just stuck in a transition period right now, and that almost always means experiencing just a taste of what the future holds.