Use the rubber grommets when mounting the hard drives?

[EvanVanVan]

The Lian Li case I bought (http://www.newegg.com/Product/Product.aspx?Item=N82E16811112300) came with rubber grommets in the hard drive cages (http://c1.neweggimages.com/BizIntell/item/11/112/11-112-300/f3.jpg). Should I use them? I tried searching but Google didn't come up with a definitive answer.

Thanks

 

[cyberjock]

Oh boy.. can of worms..

So there's a this-for-that tradeoff with the rubber grommets.. here goes.

You choose to use the rubber grommets and you get vibration protection between the hard drive and the case. Obviously a quieter computer is preferred, and the theory is that if you cushion those vibrations then it MUST be a good thing, right? Not so fast...

The rubber grommets also mean that the hard drive isn't hard mounted. So any vibration from the hard drive will be acted on the hard drive alone. It's no longer hard-mounted and screwed into the case. This could cause unwanted excessive vibrations that may shorten your disk's lifespan.

When I got to play with a vibration monitor years ago, those rubber grommets did nasty things to the actual disk vibrations. The total vibration was always MUCH MUCH worse than when screwed into the case tightly. Now, as for how "bag" that really is for the hard drives is anyone's guess. But, I take the stance that some hard drive manufacturer's recommend against the rubber grommets, and I don't have a problem with hard drive noise, so guess how I mount my hard drives?

No grommets for me.

 

[EvanVanVan]

Ok thanks for the advice. Mainly most of the arguments I read for the grommets were as you said, for a quieter drive. But I'm guessing the majority of them were for 1 hard drive in a desktop environment. Life and wear of the hard drives is probably more important in a nas than a desktop.

Hopefully my Red drives don't have errors with more than 5 drives in the box, but otherwise I'm probably leaning towards no grommet.

Thanks again.

 

[joelmusicman]

AFAIK, the 5 drive limit is mostly to scare off businesses from using WD RED instead of enterprise drives. There's no way they could actually prove that you didn't follow that recommendation.

 

[indy]

The rubber grommets also mean that the hard drive isn't hard mounted. So any vibration from the hard drive will be acted on the hard drive alone. It's no longer hard-mounted and screwed into the case. This could cause unwanted excessive vibrations that may shorten your disk's lifespan.

When I got to play with a vibration monitor years ago, those rubber grommets did nasty things to the actual disk vibrations. The total vibration was always MUCH MUCH worse than when screwed into the case tightly. Now, as for how "bag" that really is for the hard drives is anyone's guess. But, I take the stance that some hard drive manufacturer's recommend against the rubber grommets, and I don't have a problem with hard drive noise, so guess how I mount my hard drives?

I guess this is an expected result for a single disk.
However its does not necessarily hold true for multiple disks packed together as it is common for most NAS.

 

[cyberjock]

I guess this is an expected result for a single disk.
However its does not necessarily hold true for multiple disks packed together as it is common for most NAS.

What? Can you explain what you mean?

The problems I saw was that a single disk in rubber grommets had more vibration being imparted on that 1 disk than our 5 disk carriage that had 5 disks screwed into the metal cages. The issue wasn't with the number of disks in the machine. The problem was that a hard drive left to "float" on the rubber grommets had all of the kinetic energy of head motion being imparted solely by the hard disk instead of the entire computer case/rack/etc. Sure, there's "potential" that 24 disks in a 4U may impart more vibrations on all of the disks as a whole, but without someone actually doing the test and providing actual values it's only conjecture and opinion.

And I have a 24 disk 4U server that has no rubber grommets(not even optional), and I've had 3 or 4 failures in 3 or so years. So I've already proved an exception. But, I'll also agree that a single example isn't a good statistical group from which to draw conclusions from. But we're talking about laws of physics too, and you shouldn't normally find 'exceptions' to those. ;)

 

[indy]

Sure, there's "potential" that 24 disks in a 4U may impart more vibrations on all of the disks as a whole, but without someone actually doing the test and providing actual values it's only conjecture and opinion.

That is exactly what I meant.
Without testing its hard to tell if a lack of rigid mounting or resonances from multiple disks induce greater wear, and if it is even relevant as a failure cause.
Personally I have had good experiences with rubber mounting, though only on a small number of disks.
What is palpable however is the lower amount of noise generated.

 

[cyberjock]

Without testing its hard to tell if a lack of rigid mounting or resonances from multiple disks induce greater wear, and if it is even relevant as a failure cause.

Sure. But, hypothetically speaking if you have 1 hard drive with X amount of vibration and 1 hard drive with X*6 vibration, which hard drive would you assume would last longer? The ratio for our setup was something like 5.8x higher.

Then, if you check out some hard drive manufacturer's documentation they recommend against the rubber grommets.

So there's more than just some anecdotal evidence that rubber grommets might not be the best idea.

There was an article back in 2006 or so when rubber grommets hit the market suddenly and someone had a post discussing the whole rubber grommets idea. In the post he discussed the fact that the rubber grommet idea was an obvious choice back in the 1970s and 1980s when hard drives were much louder and much bigger. And what stopped them was the fact that rubber grommets were so bad that the hard drive firmware would start encountering errors almost immediately on bootup with many hard drives unable to complete their POST testing without failing because the vibrations and head movement would shake the drive around violently enough that you *couldn't* sell a computer case with rubber grommets and expect the hard drive installed to work. ;) If I had the link still I'd provide it as it was an interesting read.

 

[ewhac]

The issue wasn't with the number of disks in the machine. The problem was that a hard drive left to "float" on the rubber grommets had all of the kinetic energy of head motion being imparted solely by the hard disk instead of the entire computer case/rack/etc.

Thank you. Once explained in clear terms as this, the issue becomes obvious.

 

[joeschmuck]

Rubber grommets are still sold in many of today computer cases or even some of the quick remove drive cages have minor dampening on them. I've personally never seen a drive manufacturer recommend against grommets but that doesn't me they don't exist. Now the rubber grommets I've personally used in the past are not very pliable, they are a bit stiff but they do assist in vibration noise.

I can't think of a single hard drive that I've purchased or used over the past 5 years which has exhibited a lot of vibration. They all seem to be very quiet, even the 15K drives I have at work and of course those are packed into servers without grommets and they seem to last.

As for the kinetic energy thing... Naw, I don't buy it. I understand that hard mounting a hard drive will reduce the hard drive shell from vibrating so much but that does nothing to the head except the head would use a little more energy to keep those ultra low mass heads in place. The damage really goes to the spindle bearings for the excessive vibration. And lets keep this into perspective, mounting using grommets doesn't mean the same thing as placing it on a table or a rubber pad and watching it vibrate around. That would be damaging.

So to conclude... I feel the rubber grommets of the past and present are there to make things quiet for crappy hard drives that are created. My personal feeling is they do no harm with today's hard drives and it's a personal preference.

Just thought I'd jump in and stir up this pot.