Vibrations in WD Gold 2TB HDD, and in HDDs in general

Hi there,
I am going to use a 2 TB Gold HDD in an acoustically-controlled environment for low frequencies (<100 Hz in our case).
Actually I find vibrations @ 90Hz caused by a 3-yrs old Green HDD. I also found some similar case in other HDDs, always at 90Hz. Vibrations are measured as acoustical noise transmitted by floor by a microphone 2 meters away from the source.

My questions:

  • It seems that 90Hz is a common frequency for vibrations stemming from some (or all) of these devs, isn’t it?
  • Do exist specs about Gold (or 2TB Gold) HDDs vibrations? I actually find acoustic specs - which are excellent of course. Or, alternatively, can I be confident on the fact that Gold 2TB HDD will create neglectable vibrations?

Thanks

Simple math. WD Green is a 5400 rpm drive. 5400 revs per minute / 60 seconds per minute = 90 revolutions per second.

Faster rotational speed = higher vibration frequency.

4200 RPM = 70 Hz.
5400 RPM = 90 Hz
7200 RPM = 120 Hz
10000 RPM = ~167 Hz
15000 RPM = 250 Hz

Pick your poison. ALL spinning drives will vibrate. Every one ever made.

The AMPLITUDE of the vibration all depends on how it’s mounted. If you can’t stomach any vibration, use an SSD. If you can tolerate low amplitude vibration, mount the drive to something with more mass.

Thx Tony for the explanations.

What I also wanted to know is: do every HDD vibrate with the same amplitude? I find it hard to believe, but it may be. Who knows? Do exist specs for vibrations?

No, even two HDDs of the same model will have different amplitudes. The vibration is caused by a minuscule imbalance in the spindle due to small differences in manufacturing and/or assembly.

Whether worst-case specifications are published anywhere, I don’t know.

HDD can spin WITHOUT any noticeable vibtation, which is caused always by mounting discs with their center od mass NOT EXACTLY laying on spin axis. I have used many disk drives. Many of them nad vibrations, but some run fine and very silent.
In order to prevent vibations beeing carried to table, floor and even microphone stand, just put disk enclosure on elastic suspention, i. e. 4 silicone or foam pads. Don’t attach it to much higher mass, it is unnecessary.