Hard drive woes

Shortly before Christmas, one of my media drives (a 300 GB Maxtor) started to give warning signs that it was about to die — a number of files mysteriously developed CRC errors for no apparent reason.

I downloaded Maxtor’s PowerMax utility which gives the drive a once-over. PowerMax can run a 90 second test to give a quick estimate of the drive’s condition, or a more thorough test that lasts several hours. In the event, it took only 10 seconds to figure out my drive was quite sick and should be sent back to Maxtor for replacement. (The drive was just over 12 months old, but to my relief, it turned out to have a three year warranty. Exactly the same drive sold in the USA comes with only a one year warranty. Go figure.)

I bought a replacement 300 GB drive to back up the data (luckily, I only lost a few files), and then kicked off Maxtor’s RMA process. Conveniently, if you give them your credit card number, they will ship you the replacement drive first — you can then use that drive’s Maxtor-approved packaging to return the defective unit.

Three weeks later, Maxtor Support emailed me to say that it would be February before an exact replacement for my unit would be available, but that they’d be happy to ship me one of their new DiamondMax 10 6B300R0 models instead if that was acceptable. While RAID users might have preferred an exact replacement, I just wanted a new drive (and this one was better specced) so I told them to go ahead.

The new drive duly arrived about two weeks ago, and I decided to install it as the boot drive in my main PC; I partitioned it as a 30 GB C drive for Windows with the remaining 250 GB for my D: drive. (Yep, that’s only 280 GB, but that works out as 300,647,710,720 bytes — got to hand it to those hard drive marketing guys…)

After installation, it slowly became apparent that something wasn’t quite right with my system. Simple file copies from one partition to another (and especially from firewire drives to my D: drive) seemed much slower than they should be. Worse, while this was going on, Windows would slow to a crawl – in some cases, I could see individual window elements rendering a few pixels at a time.

It took me a while to figure out the drive was the issue – for normal use, things worked fast enough. I checked the DMA settings on the drive (Windows XP has a tendency to disable DMA without telling you, if it detects errors) but it was fine. Eventually though, I noticed that HDTach 3 showed rather erratic performance – instead of the usual smooth graph, it was very choppy.

That got me thinking, and I finally decided that the culprit might be the removable drive caddies that I use in all my systems. These are only rated to ATA66, yet the new Maxtor is an ATA133 drive. A few minutes later, I’d whipped out the caddy and connected the drive directly and — everything back to normal! I also replace my ATA66 cable with a newer ATA133 cable, which improved the HDTach results by another 10% or so.

I can only presume Windows must have been retrying like crazy before, hence the heavy CPU usage — or possibly switching briefly to PIO mode to recover from a corrupt DMA transfer? In any case, it’s good to have a system at 100% again!

Lesson learnt: adding any new hardware to a working system should always be done very carefully!