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Hard Drive Secrets

This article took a 180-degree turn, due to advances in the computer industry. This information, in 2003, supercedes the previous information.

You may have read recently in a computer magazine about the SCSI vs. EIDE debate. You may have read PC Computing's statement that EIDE drives are now as fast as SCSI drives. Amazingly, this is really true! Before we see what this means, let's get an introduction to the key characters in this drama.

SCSI still has one advantage over IDE of any flavor: it doesn't bog down your CPU to do its job. IDE, in fact, uses nine times the resources SCSI does for the same operation. With Pentium-III and faster processors, this overhead is usually inconsequential. At one time, the argument against IDE was that any average horse could have beaten Secretariat--if Secretariat had to carry 9 jockeys and the other horse had to carry only one. This metaphor illustrated that no matter how fast an IDE drive became, its resource requirements would bog down the whole system.  But, this metaphor is no longer true when it comes to CPUs because a modern CPU in an IDE system isn't carrying nine extra jockeys. It is carrying nine extra ounces on a jockey--something that may not make a noticeable difference at all.

A big advantage of SCSI is you use only one IRQ (Interrupt ReQuest) to drive up to 10 devices. This has system expansion implications that are rapidly becoming inconsequential. Let's see why.

We pronounce IRQ "Eye-Are-Que," (Hey, so am I!), but I think we should pronounce it "Irk." It really irks me that you need an IRQ for each IDE device. At one time, if you added anything to your system, you'd start having IRQ conflicts. You can run out of IRQs, and that means devices compete for processor attention--often crashing the system as they do. This made a strong case for SCSI.  In a two HDD (hard drive) system with a CD-ROM and scanner, you can free up 3 IRQs simply by going to SCSI. That leaves more for your video card, sound card, modem, and mouse to fight over. You have only 15, and most of those are reserved.

But, a way around this conundrum is to use USB peripherals and devices. A USB scanner, backup drive, mouse, CD-burner, printer, etc., and you suddenly free up IRQs. Another way around this conundrum is to abandon the single desktop model completely. Computers are so cheap these days, you can build (or buy) two IDE-based systems and network them together for less money than you'd spend on a comparable SCSI-based system. The advantages of this are immense. For example, you can back up the files of each system to the hard drive(s) of the other. You can also have one machine set aside for CPU-intensive tasks like CD-burning or whatever, while the other machine is 100% available for use. If you have a system failure in one machine (e.g., Windows needs complete reinstallation or your CPU croaks), you can still work.

Just a few years ago, SCSI was the clear champion. Today, that isn't so. If you have the older SCSI systems, it is especially not so. The IDE loading problem on a system is not a concern if your processor is at least a Pentium-III-500 , and USB resolves the IRQ issue. Plus, networking two IDE machines--perhaps an older one and a new one--will leave any SCSI "Swiss Army knife" computer in the dust. You have more than twice the available CPU power and many, many other advantages that simply make the SCSI advantages irrelevant.

So, don't spend big money on a SCSI system for your desktop. If you are in the server and RAID array world, or have high-end needs, you may want to spring for a high-end SCSI system. But for even power users, today's IDE runs circles around yesterday's SCSI. Especially if you spend the same money creating a peer-to-peer network of two machines.

Computer Resource Quicklinks Click here for: computer prints, photos, and posters. Click here to see all of our books on computers. Click here to see all of our DVDs on computers. Do you need to get in shape after spending too much time at the computer? Click here. Working the Windows Desktop The whole desktop approach ignores the fact that a computer's hard drive(s) are the electronic version of a paper filing cabinet. It also ignores the fact that people store a huge amount of files in that system. And it ignores a few dozen other facts relevant to using a computer. It's just a bad approach. The desktop assumes you don't care what files you actually work on. It opens apps, not files, and this is the pathway to problems. You can inadvertently be revising the wrong thing, if you can even find it in the first place. What you should do instead is use Windows Explorer. Microsoft tends to hide this, but it should be your standard interface with your computer, unless you don't mind working blind. You can always right mouse click the Start button to invoke it, but you should add Windows Explorer to your Quick Launch bar and several other menus in Windows. The default settings for Windows Explorer defy logic. Change these so you can actually see what files you are looking at. Enable it to show you the file extensions (unclick the insane "Hide extensions" box that is, stupidly enough, checked by default though actually there is never any reason to ever check this box). Select the option to show details. Now, you will be able to see your file size, file date, and other useful information. If you right click around a bit, you can find quite a bit of functionality in Windows Explorer. If you haven't been using this interface previously, make a point of using it now. If you always open files from within Windows Explorer, you will always be able to see all available files and select the right one. Use Windows Explorer to set up your filing system as if it's a paper filing cabinet. Save all files either on the data drive (dual hard drive machine) or in a folder on a single hard drive machine. Do NOT save files to the default locations. These never make any sense. They are typically within your applications, which is a dumb place to save them. That's how you end up with corrupted data files and it also makes file backups difficult. For single-drive users, an easy solution is to create a folder called 0files as your top-level data folder. The zero means it will show up at the top of your file list, making things easy for you. Below this folder, create you filing structure. Never store anything at the root of this folder. Think of it as the shell of a five-drawer filing cabinet and don't toss stuff in the bottom. Always put files in folders that are in drawers. With a good filing structure in place, you will always be able to find your files by simply clicking right to them. So think this out as you go and follow a good taxonomy. It's a much more effective way to work than how the zombies at Microsoft envision people working.   Recovering hard drive space Even with today's huge drives, people sometimes run out of hard drive space. The steps below can recover wasted space. Do a search for *.tmp files. Delete all of them. Then defrag your drive. Do a search for *.bak files. Delete all of them. Then defrag your drive. If you have any *.bmp files, change the format to *.jpg. This will result in radically smaller files. You need an image tool for this; if you don't have one installed already, then skip this step. Set the Properties for the drive to compress files. In Windows Explorer, right mouse click the drive name. Then select Properties. Then select Compress to Save Drive Space. This could take a while, so unless you want your machine tied up for a few hours do this process one folder at a time and then do it for the whole drive. If this issue is for your programs drive, then remove any programs you aren't using. Go to Control Panel | Remove Programs. On your data drive, zip files you aren't using. There are other steps you can take, but if, at this point, you are still low on disk space you really need to add another hard drive or upgrade one that's in your system. Or, another very cool option, is to add a My Ditto system. See our Review of the Dane my Ditto network server.