SATA Hard Drives & Activity Lights

There are two types of SATA hard drives. SATA I and SATA II.

SATA I hard drives can transfer about 150MB/sec of data. SATA II can transfer 300MB/sec of data. Besides that, SATA II drives have a few more "features" and are being built a bit more robust. So, they can be expected to last a little longer before failure.

SATA I hard drives do not have any provisions for an "activity light". Remember? They have fewer "features" than SATA II hard drives.

SATA II hard drives do have built-in provisions for an activity light and, when mounted in hard drive caddies, will provide for full activity-light function.

Vantec makes a caddy that works very nicely with all SATA hard drives. If you place a SATA II hard drive in it, you will have full, normal, activity light operation. However, if you place a SATA I hard drive in the caddy, there will be no activity light function..., unless...

...unless you are using a particular motherboard or SATA Controller Card that has built onto it the activity light output pins. Here's how it works...

Built onto the back of the Vantec caddy is a small printed circuit board with two tiny header pins. If your motherboard or SATA Controller Card also has similar activity light output pins, then you can run a cable between the pins on the back of the caddy and the pins on the motherboard/controller card and presto... you will have an activity light! The downside of this is that the SATA controller built onto motherboards and the SATA Controller Cards are usually designed to "control" 2 or more SATA hard drives. The Controller bus activity connector that is sometimes (not always) available reports only bus activity for the entire controller and not just for one specific hard drive. Still, it might be better than nothing.

The real answer to this business of having a SATA activity light is to use SATA II hard drives.

Why Should You Want A Hard Drive Activity Light

When a computer and its hard drives are working correctly, there is very little need to have an Activity Light. The problem comes when things get a little age on them and little problems begin to develop. All computer operating systems have built-in provisions that attempt to solve problems and fix corrupted files before you even know about it. And, that is exactly what happens - most of the time.

But, when the problems go on for a while, and get worse and worse, then the operating system has more and more trouble fixing the problems. The first symptoms of excessive problems is when the operating system takes longer than normal in booting the computer.

Another symptom is when the operating system goes out to one of the hard drives and starts doing a scan of it when you have not done anything to initiate the activity.

When you are using a computer with only one hard drive, you will always know when the C: drive is being accessed. Typically, during boot-up you can watch the C: drive activity light and easily see that the drive is running and running. Experience tells you that you are not going to get the computer to do much until the C: activity light stops flickering.

But, when you start adding additional data-drives to a computer (the ColorBAT BackUp Concept), unless you make a special effort to see that activity lights are connected for each of them, you will never know if the operating system is accessing a drive other than the C: drive.

For example, during boot-up, one of the data drives could have a corruption problem that the operating system is trying to resolve by scanning the drive. This type of scanning puts a heavy load on the CPU. So, until the scan is completed, you will not get much done with the computer. But, without an activity light to tell you that one of the data drives is being scanned, you might not know what the hold up is. Further, if the same data drive is always scanned during boot-up, (and you notice this because the activity light is reporting it) you might be alerted to an early warning that there is a problem with that particular drive. Taking that drive off-line and re-formatting it or replacing it could save you a serious failure when you least expected it - and save you from being down for a day or so... or worse!

Activity lights are like insurance policies - they're worthless until there is a problem, and then they are priceless!

The above picture is a close-up of the LCD panel on the Vantec hard drive caddy. The LCD reports the operating temperature of the hard drive along with a confirmation of the cooling fan and the little wheel-like image in the upper left corner appears to turn when the drive is being accessed. A warning buzzer can be set for a specific hi-temperature alarm.