Integration brings NAS to the masses
By Brian Dipert -- EDN, April 29, 2004
As multiple networked computers increasingly appear in homes; as consumers archive increasing amounts of audio, video, and still-image digital data; and as the value of that data increasingly encourages consumers to archive it for safekeeping, consumers will increasingly embrace NAS (network-attached-storage) devices (see “Speedy simplicity,” EDN, Jan 22, 2004, pg 33). Mirra’s (www.mirra.com) 80-Gbyte Personal Server has nailed the concept, but its $399 manufacturer’s suggested retail price is palatable only for SOHOs (small offices/home offices) and the most tech-crazed early adopters. D-Link’s (www.dlink.com) 20-Gbyte Central Home Drive, at $249 suggested retail price, addresses the NAS price issue but involves a capacity trade-off. And Ximeta’s (www.ximeta.com) 80-Gbyte NetDisk NDAS (Network Direct Attached Storage), at $199, makes further price and capacity improvements but isn’t a true NAS; it requires the installation of client-side software to directly access it.
Broadcom, with its BCM4780 NAS processor chip, hopes to enable its partners to hit NDAS-like price points with a full NAS feature set (Picture). Supporting both NFS (Network File System) and CIFS (Common Internet File System) protocols and now available in sample quantities, the less-than-$20 (1 million) BCM4780 integrates numerous subsystems, including a 300-MHz MIPS32 processor core, a 10/100-Mbit Ethernet MAC (media-access controller), USB client and host controllers, dedicated AES encryption and decryption hardware to prevent the transfer-rate-performance degradation that a software-based alternative AES approach would incur, an LCD controller and general-purpose I/Os, an ATAPI controller intended for optical- and tape-backup drives, and a PCI host controller. The NAS’ drive or drives connect through a separate PCI-to-ATA-bridge chip, and an 802.11-connectivity implementation requires either a wired-to-wireless or PCI-to-wireless bridge. However, the BCM4780 integrates most of the functions that the Central Home Drive, for example, requires multiple devices to implement.
The BCM4780 directly manages as many as four drives, in JBOD (just-a-bunch-of-disks) and RAID (redundant-array-of-inexpensive-disks/redundant-array-of-independent-disks) 0/1/1+0 configurations. It handles volumes as large as 1000 Tbytes, and Broadcom claims that the device creates a 1-Tbyte volume in less than 2 minutes. Its journaling file system, in conjunction with support for SMART (self-monitoring analysis reporting technology) and subsequent warning and error reporting ensure file-system and partition integrity. Broadcom forecasts that its customers will be able to achieve less-than-$100 system prices, excluding the drive or drives, and, to speed your time to market, a full-blown reference design, including a comprehensive software suite for Windows, MacOS, and Linux operating systems, is available.
Broadcom, 1-949-450-8799, www.broadcom.com.
