Look for new hard drive standards when you’re upgrading or buying a new system. The words to look for are UDMA 66, Ultra 66 or UIDE 66 and 7200 RPM. These new drives give significant improvements in your computer’s performance. They’ve become inexpensive too.

On my current system I set the computer up with a standard hard drive first, then copied over to a 7200 RPM drive a week or so later, and a few months after that, installed Ultra-66 support. So I have some subjective comparisons. The system is an AMD K6-3/450 with 2M cache.

It makes sense, doesn’t it? The faster the hard drive spins, the faster the data will go on and come off. The "normal" rotation speed for IDE has been 5400 RPM for a long time. Faster drives for SCSI are available, though. Seagate and IBM - that I know of – have had even 10,000 RPM drives for some time. They’ve always been with SCSI interfaces, and very high prices. SCSI drives are used in servers and in very high-end workstations.

The newest drives for consumer PCs are 7200 RPM, a 33% increase in rotational speed. These drives should give you a very noticeable 20% improvement in program load time. The price difference between 5400 and 7200 drives is very low, and very often the new ones go on sale with rebates.

Notice that I mention "program load time". Loading large files from disks is where you’ll notice the biggest difference; and notice it you will!. You’ll see a dramatic improvement when you turn on the computer and it’s loading Windows, and you’ll notice it when loading large programs like MS Word or MS Access. But the hard drive is used for nearly everything. The extra speed will be used when moving data to the swap file, for instance, and when caching pictures from the Internet and so on, but in my own experience it won’t be as dramatic a difference. You’ll know it’s there, but it isn’t a "wow" thing like loading Word or Paint Shop Pro.

The SCSI standard has been upgraded over time to specify higher and higher data rates, starting with 5MB/sec (in 1986) up to 80MB/sec (in 1996), making it possible to raise the data rate of hard drives themselves (or maybe it was the other way round). SCSI drives are not normally used in consumer PC’s because of their much higher price. You can do it though, and some people do, when the cost isn’t a great factor.

IDE, on the other hand, had been stuck at 33MB/sec for some time, starting with 486 systems, until recently. IDE is the standard for all personal computers other than workstations and servers. IDE drives are inexpensive (I wouldn’t have been saying that two years ago), but the recent big news is Ultra-66. It’s also called UDMA-66 (Ultra DMA-66). This new standard specifies a data burst transfer rate of 66MB/sec.; technically, "burst transfer rate" means the data transfer from the hard drive’s cache memory.

You need four things to get Ultra-66. A hard drive that supports it, a system board or alternately an Ultra-66 controller card, a special 80-wire cable and, last, a utility program that sets the hard drive to either 33 or 66.

What you’re looking for - 66 - should be obvious, but believe it or not there were many drives manufactured that are 66-capable, but set as 33 and shipped that way. Look at the specs on the box if the 66 isn’t obvious. Look for DMA Mode 3 or 4. Mode 3 is 44 MB/sec, and Mode 4 is 66 MB/sec. There’s a utility program that should be shipped with the drive, but sometimes is not, and can be easily downloaded from the manufacturer’s web site. It’s a tiny DOS program, and it’s used to set the drives speed from 33 to 66 or vice-versa. Recent drives are set to 66 out of the box. So be careful here if you’re hooking it up to a 33-only controller. A 66 controller will handle both, but a 33-only will give you drive errors if you connect a drive set to 66 to it. Boot into DOS first, and insert the diskette with the setting software and run it. Follow the instructions.

I’ve used both – several system boards and also I have a Promise Ultra66 PCI controller card on my personal system. It will simply recognize the drive and use mode 4. Look at the bootup information closely, and you should see it. Mode 4.

As you supposed, when you go to Ultra-66, the old 40-pin ribbon cable won’t work. It’s still a 40-pin ribbon cable but it now has 80 wires. The extra 40 wires are grounded to eliminate interference. It’s easy to spot, too. The cable is stiffer because it has two layers of wires and seems – to me – more fragile. It’s an additional cost unless either the motherboard or the drive comes with it. In my case the cable came with the controller card, making the Promise board a better deal for me than others. Drive cables normally come with the motherboard, and many boards do not include a 66 cable, just a 33, even though 66 is supported. The cable is expensive - $15 or so.

The Promise Ultra 66 works the same as a system board except for one thing, and I discovered it by accident. I don’t think it’s the Promise Card’s fault, but the Quantum Hard drive 33/66 utility would not find the hard drive when it’s plugged into the controller card. So I switched the cable to the (33) system board to set it. It had me going for a while. This controller card will recognize that the correct cable is being used and refuse to put it into Mode 4 if not.

A couple of interesting things about this board. All technical. It uses one interrupt (IRQ). That’s in addition to the two that your system board takes. But they’ll run simultaneously, for up to eight drives total. If you put all your drives – including CDROM – on the controller card, you can disable the system board devices both in Windows and in the bios. In that order. That’ll free up IRQs 15 and 14.

Promise is at http://www.promise.com/Products/idecards/u66.htm .

I’d bought the Quantum 9.4G UIDE66/7200RPM drive from Buycomp.com for an incredible price. It was backordered, but I didn’t care. I’d wait. When I copied the drive image over to it and installed it – with the system board that does not do 66 – I started having some program failures and some disk errors. But I puzzled over it for a while, lived with it, and in the meantime ordered the Promise card. So when I got it and installed it, I ran the Quantum utility to set it to 66, and found it already was. Errors explained. Read the manual, dummy. Of course that was how I found out that the Quantum software couldn’t find the drive at all when it was on the card.

So I got the card in, and Windows up and running, and within twenty minutes got a corrupt registry error message, requiring a shutdown. On bootup the registry utility restored the last backup and restarted Windows, with an immediate error message again, reboot again, etc., to go on forever.

So I decided to reinstall Windows SE. The first thing that Windows SE does on a reinstall is to check for a corrupt registry, and if it finds it, run a repair utility. Good. I cancelled the rest of the installation, and rebooted into Windows, and it worked for a while, but the same evening I got the corrupt registry back.

So I pulled the Promise card out, and connected to the system board and ran the Quantum utility to set it to 33, and we’re up and running fine. The machine ran like blazes with that 7200 RPM drive in it.

I used the machine with no problems for a month or so and then got the registry corrupt problem again. Some research on Microsoft knowledge base came up with the reason, a bad memory module. That’s what it said. So it wasn’t the Promise card at all, and I don’t have to send it back – I didn’t want to anyway. I bought a 64M memory module and installed it as the first DIMM, and I had no problems for another month, when it happened again. This time I didn’t repair the registry, I just pulled one 32M module out of the machine, and I’ve had no problem since. I got lucky, I had a 50-50 chance of getting the right one of two.

So at last I can install the Promise card again. I was ready to do that because I wanted my machine in a smaller case to go on my desktop, and while I was at it, I wiped the drive clean and have been installing software for four days now.

Adding Ultra66 support wasn’t a wow thing because I’d been using an older AMD K6-2/300 system while I rebuilt. I’m so happy with the speed of the new machine, I’m still amazed at how fast the programs load. For a test, I put this article on the desktop, and rebooted the machine, and as soon as Windows was loaded, I double-clicked on the document. MS Word loaded up and read this 2-1/4 page file in 2.75 seconds by my stopwatch. It was worth it. u