Quieting an 2.16GHz iMac?

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r-sparks
Posts: 17
Joined: Wed Jan 31, 2007 6:04 am

Quieting an 2.16GHz iMac?

Post by r-sparks » Wed Jan 31, 2007 6:16 am

I got an iMac just before Xmas. It's by far the quietest desktop computer I've ever owned. It's got a 2.16Ghz Core 2 Duo processor.

To cut a long story short, the computer had a low whirr, which was acceptable and even soothing. Over recent days the noise has become thinner and more whiney. Still damned quiet (I can hear the clock ticking on the other side of the room), but intrusive and annoying.

I don't know if the new noise is caused by fans, or the hard disk, or even the PSU's converter circuits (it's not the infamous screen buzz - I've checked).

But I'll have to live with it because the computer works fine and I'd imagine I'll get short-shrift if I took it in for repair. It might be that the new processors on the latest iMacs mean increased noise is the way it's got to be.

So the question is how to quieten it! Silent would be perfect, but without access to the innards we're looking at somehow rerouting the venting so that the noise is absorbed. There are three vents - on the bottom; one just behind the stand; and the main exhaust vent near the top, which is a long slit. The top and bottom vents are where most noise comes from. (The review of the 24in iMac on this site shows the vents in the photos.)

For the back I was thinking of some kind of baffle, perhaps made out of thick absorbent cardboard. Same for the bottom. This wouldn't be look too odd :)

Any ideas appreciated.

mshan
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Post by mshan » Wed Jan 31, 2007 8:17 am

My dad has a CoreDuo iMac and it is very quiet except for an annoying case fan (right lower corner). Realistically, don't think I can do anything about it, but disappointing given the cost of these Apple iMacs.

http://www.kodawarisan.com/imac_intel/imac_intel01.html

r-sparks
Posts: 17
Joined: Wed Jan 31, 2007 6:04 am

Post by r-sparks » Wed Jan 31, 2007 12:40 pm

mshan wrote:My dad has a CoreDuo iMac and it is very quiet except for an annoying case fan (right lower corner). Realistically, don't think I can do anything about it, but disappointing given the cost of these Apple iMacs.

http://www.kodawarisan.com/imac_intel/imac_intel01.html
To be fair to Apple, my iMac contains a fairly powerful processor. If this were in a Dell PC, it'd be like having a hairdryer on my desk. My iMac is whisper quiet. It's just that the pitch of that whisper is annoying :)

r-sparks
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Joined: Wed Jan 31, 2007 6:04 am

Re: Quieting an 2.16GHz iMac?

Post by r-sparks » Thu Feb 01, 2007 12:13 pm

r-sparks wrote:I got an iMac just before Xmas. It's by far the quietest desktop computer I've ever owned. It's got a 2.16Ghz Core 2 Duo processor.

To cut a long story short, the computer had a low whirr, which was acceptable and even soothing. Over recent days the noise has become thinner and more whiney. Still damned quiet (I can hear the clock ticking on the other side of the room), but intrusive and annoying.
I think I've figured this out. It's the hard disk, a Seagate Barracuda ST3250824AS Q model.

If it spins down, the sound goes, and I'm left with the gentle whoosh of the fans. As soon as I click on something, it spins up. and the sound returns. It sounds like a constant tinnitus - around the same pitch, and just about audible.

The question is, what can I do about it? The disk works fine, and SMART checks out OK. It's just a particularly noisy example. I don't think Apple will service it just because it makes an annoying noise.

I suspect the only thing I can do is replace it with a different model. Are there any notoriously quiet hard disks around? iMacs use SATA2.

stromgald
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Location: California, US

Re: Quieting an 2.16GHz iMac?

Post by stromgald » Fri Feb 02, 2007 10:55 am

r-sparks wrote: I suspect the only thing I can do is replace it with a different model. Are there any notoriously quiet hard disks around? iMacs use SATA2.
There are quieter SATA 2 hard drives out there, but I'm not sure if you can just move the operating system over like in a PC. Macintosh is notorious for making it difficult to move the OS around. Make sure this is possible before buying a hard drive and finding out you can't.

The Western Digital SE16 ('KS' and 'YS') series of drives are very good. Just avoid the Raptors and the old 'JB' and 'BB' versions. You can find them on newegg, just do a search for "Western Digital SE16". Samsung drives are also very good in terms of noise. Either would do fine IMHO. If you don't need much room, single platter Seagate 7200.9 or 7200.10 (<160GB) drives are also fairly quiet and may be cheaper, just don't get any of their bigger drives. Those drives can be whinny (like yours) and get really hot at times.

P.S. To be fair to Dell, I find that some older Dells are fairly quiet (just a soft whoosh) if they have lower power (<2.0Ghz P4s) CPUs since Dell gets custom made fans that have better noise/cfm ratio than you can get in the stores. Not sure if the Core 2 Duos fall in this category or if Dell still uses the quieter fans though.
Brother's: Antec 3000B, C2D E6600, ASUS P5K, XFX 6850, 4GB DDRe RAM, 160GB Seagate 7200.8 & 2x 2TB Caviar Green, ASUS 16X DVD-ROM, Sony DVD-RW, Corsair 400W, Thermalright HR-01, 2x Scythe 120mm Low Speed Fans
Mine: Antec NSK3480 w/EA 380W, i5-750, Gigabyte P55M-UD4, Sapphire 5750, 4GB DDR3, 60GB OCZ Agility & 500GB Seagate 7200.8, Xigmatek HDT-S964

r-sparks
Posts: 17
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Re: Quieting an 2.16GHz iMac?

Post by r-sparks » Fri Feb 02, 2007 11:04 am

stromgald wrote:
r-sparks wrote: I suspect the only thing I can do is replace it with a different model. Are there any notoriously quiet hard disks around? iMacs use SATA2.
There are quieter SATA 2 hard drives out there, but I'm not sure if you can just move the operating system over like in a PC. Macintosh is notorious for making it difficult to move the OS around. Make sure this is possible before buying a hard drive and finding out you can't.

The Western Digital SE16 ('KS' and 'YS') series of drives are very good. Just avoid the Raptors and the old 'JB' and 'BB' versions. You can find them on newegg, just do a search for "Western Digital SE16". Samsung drives are also very good in terms of noise. Either would do fine IMHO. If you don't need much room, single platter Seagate 7200.9 or 7200.10 (<160GB) drives are also fairly quiet and may be cheaper, just don't get any of their bigger drives. Those drives can be whinny (like yours) and get really hot at times.

P.S. To be fair to Dell, I find that some older Dells are fairly quiet (just a soft whoosh) if they have lower power (<2.0Ghz P4s) CPUs since Dell gets custom made fans that have better noise/cfm ratio than you can get in the stores. Not sure if the Core 2 Duos fall in this category or if Dell still uses the quieter fans though.
Thanks for the advice. I was very close to cracking open the machine and fitting a Western Digital drive I had hanging around. However, I thought I'd try Apple's support line. To cut a long story short, I'm taking it in for repair. They're going to fit a new hard disk, on the basis that a noisy hard disk probably indicates one that's going to fail soon (bear in mind that the machine is just two months old!). The Seagate model in the new iMacs should, according to an engineer I was speaking to, be virtually silent. He's never heard of a drive in this state on a computer so young. I guess I just got unlucky.

stromgald
Posts: 887
Joined: Wed Jun 09, 2004 12:45 pm
Location: California, US

Re: Quieting an 2.16GHz iMac?

Post by stromgald » Fri Feb 02, 2007 11:20 am

r-sparks wrote:They're going to fit a new hard disk, on the basis that a noisy hard disk probably indicates one that's going to fail soon (bear in mind that the machine is just two months old!). The Seagate model in the new iMacs should, according to an engineer I was speaking to, be virtually silent. He's never heard of a drive in this state on a computer so young. I guess I just got unlucky.
It's true a noisy hard drive usually indicates possible failure, but in 2 months of use, I'm not so sure. I hope its just defective, but I'm more inclined to think that its more likely just a noisy drive design since that's been my experience and follows the SPCR test results. Good luck though.
Brother's: Antec 3000B, C2D E6600, ASUS P5K, XFX 6850, 4GB DDRe RAM, 160GB Seagate 7200.8 & 2x 2TB Caviar Green, ASUS 16X DVD-ROM, Sony DVD-RW, Corsair 400W, Thermalright HR-01, 2x Scythe 120mm Low Speed Fans
Mine: Antec NSK3480 w/EA 380W, i5-750, Gigabyte P55M-UD4, Sapphire 5750, 4GB DDR3, 60GB OCZ Agility & 500GB Seagate 7200.8, Xigmatek HDT-S964

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