IntroductionA couple of years ago, Steve Jobs announced that on all Macs, SCSI was out and FireWire was in. The shock that this caused those used to using SCSI was nothing to that felt by SCSI manufacturers. Jobs wowed his keynote audience with a demonstration in which he played video from a FireWire drive. He pulled the plug on the drive and the video paused, but when it was hot-plugged – something that is potentially catastrophic with SCSI – the video carried on as if nothing had happened. With the exception of the SCSI people, everyone cheered and whooped. Yet FireWire has failed to live up to this early excitement. Although most Macs released in the past year come with FireWire as standard, this is aimed more at digital video than storage. But this is now changing, so Macworld put the new wave of FireWire storage products through their paces. The drives we thought we’d get with the advent of FireWire are not the ones to have emerged. The plan was for FireWire to replace SCSI as a connection on the hard drives. However, what we have is a kind of halfway house: a FireWire connection to an external box and a IDE/ATA (Integrated Drive Electronics/Advanced Technology Attachment) connection to the hard drive. It’s less elegant than the original idea, but it does seem to work. IDE-connected drives have historically been seen as the poor cousin of the more robust SCSI interface. Macs used to use SCSI, and PCs tended to use IDE. More recently, Macs have used IDE/ATA drives, which are a cheaper alternative to SCSI. Conversely, high-end PCs occasionally offer SCSI as a more professional solution for storage. Fuzzy on SCSI
This tradition of SCSI for high-end and IDE for low-end, has given rise to some common misconceptions. One, is that high-speed storage is strictly the domain of SCSI. However, when Macs first appeared with IDE drives, they matched their SCSI equivalents, because, interfaces aside, the drive mechanisms are identical. When IBM or Quantum make a hard drive they may turn out as many as 12 variations, all with different interfaces – including the various SCSI flavours, IDE/ATA and even Fibre Channel. Drive speeds remain constant – but the options on how to transfer data varies. Performance variations are minimal, but there are times when SCSI is best – when running a number of drives working either independently or as a RAID array, for example. This is because SCSI can handle drives simultaneously. IDE/ATA is designed only for single drives – even though it can be pushed to handle up to two or three. So the fact that they use IDE/ATA behind the FireWire connection doesn’t impact on performance. FireWire runs at 400 megabits per second (Mbps), which translates to around 50MB per second. This sounds slow compared with the 160MB per second often quoted with Ultra160 SCSI. This figure refers to maximum available bandwidth, rather than actual single-drive performance. Even with a RAID array, 160MB per second remains only theoretically possible with Ultra160 SCSI. What, then, are the benefits of FireWire drives? First, new Macs don’t have SCSI. If you’re determined to own a SCSI drive, you’ll need to spend extra cash on a SCSI card to drive it. Of course, if you’ve an iMac, or even a new Cube, SCSI isn’t an option at all – leaving you with FireWire or USB. If you’re the owner of a Mac that doesn’t have FireWire, then USB is your only option. USB, though, isn’t ideal for storage because of its 1.2Mbps speed limitations. FireWire is the best all-round option. If you think all FireWire hard drives are created equal, think again. Although any manufacturer can put together a hard drive, an interface and a box and sell a proprietorial FireWire drive, there’s more to it than that. The key issues concern the quality of components used and the support and warranty offered. All the drives tested performed reasonably well, except for the Archos models. These come with a choice of adaptors: USB, FireWire or, for PC users, a Serial connection. In order to support this choice of interfaces, performance falls to almost USB levels – making Archos drives a poor deal for FireWire-based storage. However, they are portable – and therefore useful for making backups on the road. One of the main reasons for needing extra storage is to accommodate large files – typically digital video. A FireWire digital camcorder and iMovie make for a storage-hungry Mac. A five-minute iMovie can swamp smaller drives, and it won’t be long before you’re looking for bigger models. But there remain questions about how suitable FireWire drives are for this purpose. In our tests, getting video to record to a FireWire hard drive from a DV video camera led to dropped frames – a disaster when video editing. We got better results by recording directly to the internal hard drive. The fault is likely to be the bridge between the FireWire and IDE/ATA, because FireWire can obviously handle the required 5MB per-second rate – the video is being carried to the drive via FireWire anyway, and the internal IDE/ATA drives found on DV iMacs can also handle data at that speed. Alternatively, the problem could be because the two in-built FireWire ports are being used simultaneously – one for the camera and one for the drive. All the tested drives are theoretically fast enough for video editing, but there are limitations on how you can use them. If you’re serious about video, it may be worth paying extra for SCSI-based storage. This is unfortunate, because FireWire has so much to offer – but even the occasional glitch can ruin what would otherwise be a great video. Video editing worked perfectly well from the external drives, though. If you have a big internal drive, you can capture to that and transfer the files to the FireWire drive without any problem. When it’s time to transfer the edited footage to tape, simply switch the final product to the internal drive again. This isn’t an ideal solution, but is better and cheaper than most other options. Portability
If you frequently work on the road, it’s possible you’re armed with a PowerBook stacked with critical data. This is far riskier than storing information on a desktop machine, because laptops not only get dropped, but stolen. It’s possible to use Zip disks, or even portable CDRs – but there’s nothing so reassuring as having a complete hard-drive backup, ready to be transferred to a new or repaired machine. A few of the drives tested are portables, including the Archos MiniHD and the VST. Just remember, keep your backup in a different bag to the PowerBook. Only one of the drives tested – the SANcube – takes a novel approach to storage. The SANcube isn’t a simple storage add-on. The SAN stands for storage area network, which means its a hard drive accessible by more than one user via FireWire rather than any ethernet. Essentially it’s a big box loaded with three hard drives. On its back are two or more FireWire ports. Unlike a normal FireWire drive, the ports are not for daisy- chaining peripherals, but for attaching to individual computers. This means each drive can be allocated a different user, with maybe one shared by all. The disappointing thing is that, in practice, the SANCube doesn’t allow multiple accessing of files from different machines. The solution is software called AccelWare. This allows access privileges to be swapped as and when the users need it. It isn’t the most elegant solution, but if you’ve ever needed to transfer 10GB of data over a network you’ll know elegance isn’t the primary objective.