Future Variants/USB 2.0

Implementing Serial ATA on today's technology

For backward compatibility with older motherboards and hard drives that lack a Serial ATA interface, dongles or adapters could be used. However, keep in mind that there are limits to how far legacy components could be supported.

In any case, we were shown a figure summarizing the various potential implementations for legacy support: dongles (or adapters) used by both the motherboard and hard drive, a second situation where the motherboard itself could use the dongle while connected to a Serial ATA hard drive, or vice versa, a motherboard with a Serial ATA interface connected to a Parallel ATA hard drive.

To demonstrate the feasibility of the technology a system was setup with dongles on both the hard drive and motherboard. The system ran through a number of Microsoft Office applications without error.

Installation/Future Variants

Another important aspect of Serial ATA is ease of installation. There will be no need to configure Serial ATA hard drives as Master/Slave since Serial ATA is a point-to-point protocol. The initial release may also be hot swappable with later versions adding system power to the cable.

So when should we expect Serial ATA and what kind of performance will it offer?

The Serial ATA roadmap calls for three "generations." The first generation is tentatively set for release during the middle of next year with a data rate of 150MB/second. Generation 2 is anticipated to double the transfer rate to 300MB/sec when it debuts in the middle of 2004, and the 3rd Generation will double the transfer rate yet again in 2007. Keep in mind all dates and transfer rates are speculative at this point, no official details have been confirmed.

USB 2.0

For connecting peripherals such as joysticks, mice, and speakers, USB is quickly becoming the standard.

Current USB 1.1 devices operate at a data rate of 12Mbps; USB 2.0 boosts the speed to 480Mbps. USB 2.0 is also backward and forward compatible with USB 1.1, meaning that USB 1.1 devices can operate on USB 2.0 hubs at 12MBps just as USB 2.0 devices can operate on USB 1.1 hubs at 12Mbps. In fact, USB 2.0 uses the same cables and connectors as USB 1.1.

Boosting the speed to 480Mbps won't improve the performance of your mouse or keyboard, rather it is intended for high-resolution video conferencing cameras, high-end scanners, printers, portable storage devices, and broadband Internet connections.

Does USB 2.0 replace Firewire?

With the data rate increased to 480Mbps, USB 2.0 will actually be faster than current implementations of Firewire. (1394) However, USB will continue to focus on connecting PC peripherals, with Firewire aimed for consumer electronics devices such as digital camcorders, DVD players, and digital televisions.

USB 2.0 devices should begin shipping sometime during the second half of this year.