In the past few years, increasing hard disk transfer rates have forced the ATA interface to be continuously updated beyond its limits. Consumers have adopted new uses for their computers, which require vast amounts of storage for digital audio and video, file sharing, and other data-intensive transfers. Serial ATA (SATA) was developed to overcome the limitations and bottleneck of the Ultra ATA interface. Serial ATA drives have become popular not only for their next-generation transfer rate and speed, but also because their small cable size allows for maximum airflow.
Parallel ribbon cables are an absolute pain, and have many drawbacks. They can only be 40cm, which makes drive installation difficult in larger cases. Many times drive placement requires that a ribbon cable be twisted 180 degrees, which can twist and distort the cable, causing a kink in the cable that degrades performance. Airflow within the case can become severely limited with the use of multiple bulky ribbon cables. Rounded cables help, but other limitations of the ATA interface still exist.
S-ATA’s small transfer cable has caught the attention of modders because they are more flexible and allow users to easily route the cable throughout their cases. Up until recently there really weren’t a lot of modded SATA cables, and we were stuck with the standard red or black cables that came with our motherboards. These OEM SATA cables are generally very short, at around 15 inches, which prevents a lot of clever cable routing even in smaller cases. Serial ATA cables are begging to be routed, as they are so thin they can easily fit behind case components and can be tucked away without being seen, leaving one’s case looking so much neater.
Mad Dog Multimedia has answered the modder’s pleas for a tricked-out SATA cable. These cables feature the standard speeds for SATA-2 as well as some additional enhancements. These cables are UV reactive and are slightly more responsive than an OEM cable. Mad Dog Multimedia has also implemented a locking mechanism in the connector head to prevent accidental unplugging. They come in 3 different colors (blue, green, and clear), which provides more than just a custom look: you can use a set of colors to visually designate particular drives or clusters of drives.
Mad Dog’s UV SATA Cables are designed with a secure locking system and a flat design that will enhance airflow to give your rig the competitive edge you want and need. We know that you “play hard or don’t play” so we ensure the Uncompromising Excellence you demand is found in all of our Techie Toyz UV cables.
Features
- long 37″ length
- Supports speeds up to 150MB/sec
- Glows under UV light
- Locking 8mm wide connectors provide connection security
- Flat design to enhance airflow
- EMI shielding
- Hot-plugging capability*
- Overlapping commands*
- Tagged command queueing*
- 4 signal wires, 3 ground wires*
The parallel ATA specification has defined the standard storage interface for PCs since the protocol was introduced in the 1980s. Parallel ATA led for three main reasons, low cost, broad operating system support, and steady evolution. Parallel ATA evolved to support higher speed and performance while maintaining backward compatibility with older ATA devices. However, for a variety of reasons, including performance headroom, cabling issues, and voltage tolerance requirements, a new storage interface is required. Therefore, the Serial ATA Working Group was formed.
Because it combines software transparency, low cost, scalability, and design flexibility, Serial ATA has attracted widespread industry support through the Serial ATA Working Group. APT, Dell, Intel, Maxtor, and Seagate are jointly leading this initiative, with broad industry support from over 80 companies that make up the working group.
Optimization of any high-speed digital bus design in fact requires careful consideration of analog design issues. Undesired analog effects associated with parallel data busses such as crosstalk, ground bounce, ringing, and clock skew have become major design constraints for the Ultra ATA interface, which is forced to maintain compatibility with legacy parallel technology. These same issues are expected to become critical roadblocks to further Ultra ATA speed increases. Serial ATA alleviates many of these problems by transitioning to a serial data bus. The intent of the following section is to first present the design methods required to achieve the current Ultra ATA data rate and illustrate the complexities of further speed enhancements to the parallel technology. In each case, the paper will describe how the Serial ATA bus architecture overcomes these complexities to extend the performance roadmap of ATA.
Drawbacks of parallel ATA
- Crosstalk results from magnetic fields generated from transitioning currents being coupled into neighboring current loops, similar to the functionality of a transformer. The magnitude of the crosstalk is proportional to the rate of the change in the current and the amount of coupling between the current loops. Thus it is most apparent in parallel busses where multiple adjacent lines may be switching in the same direction at the same time and inject a noise voltage onto a victim signal.
- Timing – The 1.5Gbps transfer rate requires bit transitions and reception to occur within 0.667ns. The maximum allowed switching time is 0.273ns, much faster than the 10ns transition time allowable for Ultra ATA. However, as seen in the following sections the electrical design parameters of the serial bus are more tightly controlled. Serial ATA can thus meet and surpass the timing required to deliver throughput comparable to that of Ultra ATA.
- Ground bounce is most problematic when several signals switch at the same time or when using high-speed drivers, both common with parallel data busses. The instantaneous power draw is such that the decoupling capacitors for the device cannot supply the necessary current and the supply voltage sags. If the voltage decreases enough, the change can be mistaken as a bit transition.
- Ringing results from impedance changes in a signal path in systems in which signal rise time is close to or faster than the path propagation delay. When this condition holds true, the signal path must be seen as a distributed system, implying that all points on the signal path may not be at the same voltage at the same time. As the signal propagates down a path, the voltage magnitude is related to the effective impedance up to the point in the signal’s flight. If this impedance suddenly changes, the voltage temporarily increases to maintain the current flow. This voltage reflects back along the transmission line to the source, where if not fully damped may reflect again to the receiver, and may repeat until effectively damped. This causes oscillations in the voltage, or ringing, on the transmission line.
- Clock skew results from discrepancies in transmission path delays between clock and data signals or signal degradation of the clock signal. If the clock trace is shorter than the data lines, for example, the clock signal may arrive at the receiver before the data lines have stabilized, thus registering incorrect data. Alternatively, ringing or noise on the clock line can delay the clock transition relative to the data switching, possibly violating data hold time.
The cable’s EMI shielding can be easily seen through the translucent plastic tubing, and have the same feel to thick Monster speaker wire. The thin locking mechanism on the connector head is made of thin aluminum and have two raised points to grab onto the drive socket. To release the cable you much press the lever down much like releasing the clip on a network cable. The locking mechanism also provides a clue to the orientation of the plug, which takes the guesswork out of connecting the cables.
The cables are very easy to work with. At first it may seem like the cables are so long that you won’t know where to fit the entire length. The cables are more flexible than stanrdard OEM SATA cables, which tend to be a little stiff and show every little kink and bend in the cable. The extra length of this cable really allows you to route the cable through every nook and cranny in your case and still reach the destination. I routed my cables under the hard drives, through a hole, on the backside of the case, and finally emerging near the top of the motherboard right where the SATA ports are. Shorter cables forced me to block the view of other components or tighten the cable to the point where it looked like the connector might snap. 39” length is plenty of room for even a large server case.
Testing
The cables look nice and all, but we need to make sure that the performance isn’t degraded, either through the legnth of the cable or build quality. Tests were performed on the excellent Western Digital 250GB SATA2 drive with 16MB cache. HDTach was run several times to confirm consistent readings. Below are the specifications of our test system:
- AMD Athlon 64 X2 3800+
- Asus A8N SLI Deluxe nForce4 motherboard
- Western Digital 250GB KS HDD (16MB cache SATA2)
- Windows XP SP2
- HDTach 2.61
HDTach shows that the Mad Dog SATA cables perform about the same as a regular OEM SATA cable. Maximum read speed is 66MB/sec for both cables, and minimum read speed checks in at 53MB/second. There is no performance degradation even though the Mad Dog cable was tested against a much shorter OEM cable.. The HDTach test was run several times, and each result varied slightly, but was within 1% tolerance. The main objective here was to determine that the cable build is as good as an OEM cable and does not result in performance loss.
Conclusion
Those that see the value of Monster audio cables and other ultra-quality gear will be drawn to these SATA drive cables. They perform as well as a standard cable, but look much better and are easier to work with. It it wasn’t for the steep price, this cable would easily reach a 5 out of 5. If price is no object, then these are the best SATA cables you can buy.
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