In order to =answer your question we will have to know:
- What make and model drive(s) each different make and model is different
- are the drives SSD, 5,400 RPM, 7,200 RPM, or optical drives?
- What make and model enclosure will the drive be in?
- Does the enclosure have a fan, a heat sink, or no heat control?
- If the enclosure has a fan, how heavily are you using the enclosed drive? The more it is used the more and faster the fan will run.
I have four external enclosures sitting in front of me, and they range from silent to pretty noisy and the noise level depends on what they are doing. A dedicated optical drive enclosure is silent when playing an optical disc, but both the drive and the fan hum and buzz while burning. Another enclosure that has no fan and a SSD drive is absolutely silent all the time. Another fan cooled enclosure has an HD, an optical drive, and SD card slot. There is never a peep out of it using only the SD card, and even hammering pretty hard on the Toshiba 2TB HD the main thing noticed is the flashing blue LED, but start burning an optical disc and the fan noise is very noticeable. Another fan cooled enclosure with an industrial grade HD is noticeable any time it is switched on a result of both fan and drive noise.
I never notice noise from my backup drive because it is in a Time Capsule located a distance from the computers and has no fan.
If you want to minimize noise
- Avoid "industrial grade" drives as they tend to be noisier than consumer grade drives from the same manufacturer
- avoid fan cooled enclosures because no one has figured out a quiet fan
- avoid 3.5" inch drives in preference for the smaller and generally quieter 2.5" laptop drives even though that will limit you to around 2TB capacity at this point in time
- accept slower performance and use 5,400 RPM drives because they tend to run cooler and in the 2.5" form factor that is the best the 2TB drives can do
- If you have a bottomless bank account consider using all SSD (1TB SSDs are available for as little as $500)
- Avoid optical drives. Even in uncooled enclosures they hum and/or buzz while burning.
- consider using network attached drives in another room or closet where you won't hear them.
