As hard drives get bigger and faster, the interface between the drive and your PC's motherboard must evolve to handle the increased speed. ATA/100 hard drives, announced this week by Quantum, should be up to the task. The latest incarnation of the ubiquitous IDE interface, ATA/100 transfers data at burst rates of up to 100MB per second. Typically with IDE, sustained transfer rates are much slower. Quantum developed and patented the technology, as it did the earlier ATA/33 and ATA/66 interfaces. And as with prior versions, licenses are free to hard drive and PC makers. Also like earlier interfaces, the ATA/100 specification is likely to be called by several names by different vendors, including DMA-100 or Ultra-DMA 100 (although technically, the DMA moniker refers to the protocol used to transfer the data, not the interface itself. Industry sources expect a quick ramp-up to ATA/100-based products, unlike ATA/66. Quantum introduced that interface in 1998, but it didn't become common until this year because of interoperability glitches. Quantum has worked closely with PC, drive, and chip set manufacturers while developing ATA/100, says a company spokesperson. Also, the new interface is said to be easier for designers to work with than ATA/66. ATA/100, however, will be yet another interim speed step. The SerialATA interface, now in development, will initially offer burst transfer rates in the 150MB-per-second range, and will eventually exceed 200MB per second. SerialATA products are expected to become available within the next two years. Intel’s new 820E chip set will support ATA/100, and some manufacturers expect to ship PCs with the interface as soon as this month. Supporters include Acer, Compaq, Dell, Fujitsu, Gateway, HP, IBM, and NEC, which all plan to offer ATA/100 systems. Add-in board makers such as Promise Technology are expected to offer after-market ATA/100 adapters for PCs with a chip set that doesn't support ATA/100. Although Quantum doesn't expect to ship ATA/100 drives until fall, other major drive makers have more immediate plans. Starting this week, Maxtor is shipping selected drives with built-in ATA/100 compatibility. They include the 7200rpm DiamondMax Plus drives and the 5400-rpm DiamondMax 60 and DiamondMax 30 VL, all available in capacities up to 60GB. In addition, Seagate recently announced a line of low-cost, high-capacity ATA/100 drives for release in July. Seagate's 5400rpm U-Series 5 is available in capacities from 10GB to 40GB. In August, the company plans to ship AV versions of drives for consumer electronics devices such as video recorders. Besides the ATA/100 interface, the drives use Seagate's Sound Barrier technology, which the company claims makes them virtually silent. The 40GB AV model can hold up to 60 hours of TV-quality video, and Seagate says its ATA/100 interface will let the drives record up to four streams of video simultaneously. Western Digital plans to ship an Ultra ATA/100-enabled 7200 RPM WD Caviar hard drive in June. All ATA/100 drives are backward-compatible with earlier PCs that use the ATA/66 or ATA/33 interfaces, although you need an ATA/100 interface to take advantage of the full speed. The drives will use and require the 80-line low-noise ribbon cables first introduced for ATA/66 drives.