Hard disk hum driving me mad

[gilesjuk]

Whenever a add a second hard disk it just hums, oscillates every 1.5 seconds, hum...hum...hum.

I've tried three brands, samsung, maxtor and seagate. They're all the same.

Anyone had this problem and found a cure? it's driving me mental. I'm thinking of using external drives, which s daft given the nature of a Mac Pro. It's just poor design.

 

[gilesjuk]

I've reduced the hum a little by slackening of the screws on the hard disk carrier a little. But I still can't close the catch on the back of the case as this amplifies the hum.

 

[jonnyd]

Wierd. I've got 4 in mine, and it's silent.

Do they do it in all the bays? Maybe the actual bay assembly itself is loose.

Strangely enough, I have an external HDD in the office for backups that makes a terrible racket . . . I hope you don't buy one of those

 

[cwa107]

I've reduced the hum a little by slackening of the screws on the hard disk carrier a little. But I still can't close the catch on the back of the case as this amplifies the hum.

I've yet to see the innards of a Mac Pro, but having built a number of PCs in my time, I can imagine what you're experiencing. The vibration can cause some humming. Many computer manufacturers use rubber isolators to dampen the noise. This kit might help - it comes with silicone washers that you can use on the mounting screws to eliminate metal-to-metal contact.

 

[gilesjuk]

Wierd. I've got 4 in mine, and it's silent.

Do they do it in all the bays? Maybe the actual bay assembly itself is loose.

Strangely enough, I have an external HDD in the office for backups that makes a terrible racket . . . I hope you don't buy one of those

What brand drives?

I'm coming to the conclusion that only WD drives are quiet enough.

Also having more than two probably results in a constant hum, not and in and out phasing like Im getting.

If I strip it down to the WD drive it's fine. I just moved everything to a 500GB Maxtor and im using that solo and I still get the hum.

 

[gilesjuk]

Moved drive to bay 2 and it's better. If i lock the catch it is louder.

Being as music is one of the hobbies I just can't abide noise.

Constant noise is fine, humans are able to ignore constant noise, but we can't ignore variations.

 

[dtravis7]

Wierd. I've got 4 in mine, and it's silent.

Do they do it in all the bays? Maybe the actual bay assembly itself is loose.

Strangely enough, I have an external HDD in the office for backups that makes a terrible racket . . . I hope you don't buy one of those

What brand and model is the external so I will be sure to avoid it?

 

[jonnyd]

I've yet to see the innards of a Mac Pro, but having built a number of PCs in my time, I can imagine what you're experiencing. The vibration can cause some humming. Many computer manufacturers use rubber isolators to dampen the noise. This kit might help - it comes with silicone washers that you can use on the mounting screws to eliminate metal-to-metal contact.

The mounting screws in the Pro are silicon, IIRC. They don't actually 'screw' to anything except the hard disk, which you just plug in using a guide slot.

But seriously, you should check out the guts of a Mac pro (or any mac in fact) - that's one of the things that I particularly like about them. The engineering and attention to detail is astonishing. Every wire immaculately routed, every part of the frame designed to fit together properly. I have a bunch of IBM fileservers in my office here, which in comparison to the Mac look like they were built in an episode of Junkyard wars. As a PC engineer you'll enjoy it.

Gilesjuk - I don't recall what the original one was (the 160 that comes with the computer), but the other 3 are Seagate Barracudas.

If it does it regardless of which drive you use, it is actually the drive? Could it be something like the sata cable, when attached to a drive, is resting/pushing against a cooling fan or something? I don't actually recall how they connect, as they're just plugin jobs, but is that possible?

 

[gilesjuk]

This is an Intel Mac Pro, they are different to the G5.

There are 4 hard disk sleds. They are all metal and have metal screws.

The drives hang upside down (probably part of the problem, some drives aren't designed for that) and are screwed to the sleds which slide into the case and the SATA connectors of the drives slide into sockets on the boards (there are no cables).

The problem is some drives do create vibration and the thickness of the case, the rigidity means the vibrations are not dissipated. A PC case typically has thin sheet metal to hold the drives and these are suspended in the middle of the case with no connection to the outer case.

In the Mac pro the locking mechanism for the drives means vibrations from the drive bay can pass to the outer case as they become directly connected.

The Mac Pro is too rigid, you need hard disks with very well balanced motors so there is very little vibration.

 

[jonnyd]

This is an Intel Mac Pro, they are different to the G5.

There are 4 hard disk sleds. They are all metal and have metal screws.

The drives hang upside down (probably part of the problem, some drives aren't designed for that) and are screwed to the sleds which slide into the case and the SATA connectors of the drives slide into sockets on the boards (there are no cables).

The problem is some drives do create vibration and the thickness of the case, the rigidity means the vibrations are not dissipated. A PC case typically has thin sheet metal to hold the drives and these are suspended in the middle of the case with no connection to the outer case.

In the Mac pro the locking mechanism for the drives means vibrations from the drive bay can pass to the outer case as they become directly connected.

The Mac Pro is too rigid, you need hard disks with very well balanced motors so there is very little vibration.

Sorry - I'm getting confused betwen the two. I have one of each . . . you're right, it's the G5 that you put the silicon screws into.

I'm still convinced it must be soleveable - as I say, mine certainly doesn't do it, and it'd drive me nuts if it did.

 

[gilesjuk]

Must be my hard disks then.

I'd be happy taking a performance hit and dropping to 5400 RPM for basic storage. But it seems 7200 RPM is entry level now.

 

[jonnyd]

Must be my hard disks then.

I'd be happy taking a performance hit and dropping to 5400 RPM for basic storage. But it seems 7200 RPM is entry level now.

I assume the machine itself is on a level flat surface? If it's wonky maybe the extra disk is tipping it somehow.

I'm really groping in the dark now, aren't I . . . .

 

[renegade]

My Mac Pro has 3 WD 500GB units and one WD 160GB unit installed, and no hum, vibration or noise from any of them.