Conclusions
What we have said in this article comes down to two major points. First of all, don't be swayed by myth or biased opinions based on factors that do not apply to your situation. In the world of the DAW, there is enough evidence to say that either SCSI or IDE can offer the full level of drive performance necessary to take your system to its full potential. Although there are places for SCSI where IDE dare not go, one of them is NOT the digital audio workstation. Here, IDE can outperform SCSI just as often as SCSI can outperform IDE, in both cases usually not significantly and not even consistently. The format is not the issue. The drive is the issue. You're looking for high sustained throughput as made possible by fast rotation speed, quick average seek times and high areal density. Where the choice of interface comes in is the way you intend to use the system when in non-streaming mode.

The specifications regarding the interface data transfer speeds are, for all intents and purposes, irrelevant in DAW operations. This isn't to say that it isn't a good idea to have a fast interface, just a reality that the specification of concern is the sustained throughput of the drive, not the burst speed of the interface. IDE drives that use a UDMA66 interface (66 MB/sec) or even the new UDMA100 interface (100 MB/sec) being offered by Maxtor and Seagate cannot hope to sustain that rate. SCSI drives and host adapters designed to burst at 160 MB/sec or even higher are likewise limited by the drive's sustained throughput. With very few exceptions, any drive, IDE or SCSI can't begin to saturate the interface it's connected to during media streaming regardless of the advantages of these high interface speeds for "normal" desktop and server application demands. Even the new IBM packetized SCSI interface, although a minor wonder in server applications, can't help much in streaming media because the advancement was made in the device-to-device transfer setup protocols, not in the way the data itself is moved. The simple fact is, all other factors being equal, the type of interface the drive uses is not a very important factor in a DAW based strictly on the drive's ability to stream data.

A DAW system with two or maybe three disk drives and a UDMA compliant CD ROM will likely lead to the IDE choice. These drives, well chosen, will offer all of the performance necessary to satisfy the software accessing them and the CPU running them. In fact, it is almost ridiculous to even consider the idea of ever using all of the tracks these drives can make available, especially in the face of the limitation placed on that track count by mixing overhead and real time effects. On the other hand, if you want to use more total drives than four, are running additional hardware that needs the extra IRQ that the second IDE channel eats up, or plan on using the system for server-level activities when not acting as a DAW, then you must expend the extra cash and go SCSI. However, this is not because the interface is better for operating a DAW, but because the demands you are placing on your system go beyond that required of a DAW.

Another consideration is the case of wanting to process large projects at 24 bit depth and 96KHz sample rates. This might warrant a 10K or 15K rpm drive for its higher throughput. This will limit you to SCSI until future IDE drives pick up the technology. That said, keep your eye on the Maxtor multi-processor drives when they come out and on other advances in IDE drive technology like the Fujitsu. It could end up making you want to dump SCSI and go IDE for the fastest drives instead of the other way around. Obviously, if you already have an investment in SCSI, you can stay with SCSI or you can add IDE drives to a SCSI-only system for a lot less money. Providing your system doesn't fall in the categories mentioned above, you will have the same level of additional performance either way.

The second point to be made here is that a lot of a DAW system's performance hinges on the way the user has configured it. A well tweaked system of modest means can outperform a cutting edge system that has been poorly set up. Use bus mastering - period! It doesn't matter what format you select, just make sure your IDE bus mastering is active or your SCSI host adapter is of the bus mastering persuasion. The savings in CPU time will add more "real world" tracks to your DAW than any changes you could make to the the drives themselves. Buy more RAM! You want to make a big performance difference? Buy more RAM. After 256 MBytes, you can start to relax a bit and think about a faster CPU and/or better mother board. Remember, the disk drive isn't the only hardware in a DAW that directly effects your performance. By the same token, save up and buy good software. Nothing sends a DAW out a third floor window faster than crummy software.

Use good judgement when selecting the other hardware for your DAW. Don't get dazzled by the top-of-the-line video cards as they can significantly degrade DAW system performance. Also, keep up with the latest drivers for your sound card. It doesn't hurt to cruise the manufacturer's web site once each month or so just to see what might be new.

Make the tweaks to your virtual memory, your "System Type" settings and your system cache as discussed in Part 1. Pay attention to your drive partition set ups and your FAT cluster size, also mentioned in Part 1. Keep your DAW uncluttered with programs or Windows features that cut into your CPU time from the background. These include anti-virus autoscan settings, autoinsert notification for CD ROMS, screen savers, power monitors and so on. If you use the DAW for other computing tasks, check thoroughly for conflicts after each new hardware or software install. When confronted with very demanding projects, decline network connection at boot-up to save a few CPU cycles there too.

Participate or at least monitor news groups that focus on DAW issues. There's a lot of information there from fellow users that have hands-on experience to share. Just be sure to take anything you see with the necessary grain of salt. Much myth, bias and mis-information can be found anywhere "the average user" is allowed to post without peer scrutiny, so select the good news groups if you want advice worth following.

Finely, keep your eye on the ball. Remember what you want to do with this DAW - make music. This is the absolute bottom line and at some point it isn't so much the equipment you have on hand as it is the way you use what you do have. Creativity is a human process, not a function of gigabytes or megahertz. Once you have a level of performance you can be creative with, don't get distracted obsessing over more and better. Allow your system to evolve through use, not because you feel there's no point going on unless you have the best and fastest. Leave such folly for network geeks being paid to obsess. As the late Frank Zappa said, "Shut up and play your guitar." Good advice to give yourself when your eyes get bigger than your needs.

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