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Quieting a Mirrored Drive Door Power Mac G4 Desktop Macs
I have owned an awesome Apple Powermac G4 for about two years now. It's a Dual 1Ghz machine, which is commonly known as the Mirrored Drive Door (MDD) model due to its mirror finished optical drive doors. It has been a faithful servant so far for all sorts of stuff like video editing, music production, photos, web surfing, email and business duties, to name just a few.

I noticed when I first got it that it was a bit noisier than my old G4 533 Power Mac, but until my girlfriend's mother complained that it kept her awake all night, I didn't really take much notice of it. After that, though, it started to drive me crazy and I started a long campaign to quieten the thing down.

First thing I did was search Google for information on how to do it, and I found this page, which documents in detail how to replace the main 120mm cooling fan.

After trying one fan that just didn't cool the G4 well enough, I found (on FrozenCPU.com) a SilenX 120x120x38mm fan (18dBA; 90CFM) which is whisper quiet. It also cools the Mac just as well as the original Delta fan that came from Apple, only it's about 300% quieter. It made a big difference.

I also read about a software modification to Mac OSX called Nap Mode, which to cut a long story short, basically cycles the processors down into a "mini sleep" sort of mode, reducing the temperature and therefore the noise from the fans is quieter. This made a massive difference, but also added a new noisy high-pitched sound from the power supply fans. Nap mode can be installed from For G4 MDD owners, you must download version 3.5.2 of CHUD from this page; later versions do not work with MDD Powermacs. Some other models of Macs come with Nap Mode enabled as standard, like the G5 Power Macs and the PowerBook G4, so it's not a risk to use. Read more about nap mode on the MDD.

After more research, I found that another main source of noise is from the standard power supply fans that come with the MDD G4. So I chose to replace these with the fans that come on the Thermaltake Volcano 5 heatsink and fan combination -- the Everflow model F126025DH, which spin at 4550rpm with a maximum airflow of 32CFM and a noise level of 31dBA. These are actually the same fans as recommended on the above instructions at xlr8yourmac, so I was confident that they would do the job. The installation is not for the faint hearted, so if you're not good with electronics and fixing things, I wouldn't attempt it. This made a big difference once again.

I also chose to put a piece of material between the power supply and the case, as described here.

After all these measures, I now have a Powermac G4 MDD that is whisper quiet. A full description of this process is posted on my blog, if you need more details.
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Just to clarify a point...
Authored by: dalex1000 on Feb 28, '07 09:04:13AM

Off topic, but....kept your "Girfriends Mother awake" !!?? Please say your Mac was in a guest room ;)



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Just to clarify a point...
Authored by: trevbucky on Mar 01, '07 08:23:14AM

Yes she was in the guest room, but the Powermac is in the adjacent room. It was so loud you could hear it humming & sometimes roaring from the other end of the house.



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Quieting a Mirrored Drive Door Power Mac G4
Authored by: macevangelist on Feb 28, '07 09:28:50AM

I was introduced to a couple of MDDs that had a thick layer of dust in between the outer plastic and the inner metal casing on the lower front. Removing that dust helped the fans to be more quiet.



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Get rid of trapped dust so system runs cooler too!
Authored by: Peter Kappesser on Mar 01, '07 12:01:54AM

I'll second the notion on the dust trapped between the outer plastic casing and the inner metal chassis -- this also affects models such as my G4 Gigabit Ethernet (the case style previous to the MDD). My power supply fan began failing intermittently, causing the computer to shut off abruptly when the CPU temperature reached 80 degrees Celsius. I began monitoring the temperature while waiting for a replacement power supply to arrive, and it was normally operating at around 70 degrees. (I kludged up an external fan as a backup.) I discovered all the trapped dust when I disassembled the computer to replace the power supply, and now it operates in the upper 50s. I wish I'd thought to take a picture of all the dust!

You can probably get rid of (most) of it without disassembling the computer by using canned compressed air, inserting the plastic straw between the outer plastic and the inner metal chassis. Do it in the garage or somewhere because it'll blow out a lot of dust!

I recall reading somewhere that the speed of the main fan on the MDD models is thermostatically controlled, so eliminating the dust makes the fans run slower and thus quieter.



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Get rid of trapped dust so system runs cooler too!
Authored by: doughnut on Mar 01, '07 03:09:02AM
My G4 also gets a regular clean out of the dust that builds up - and I notice a drop of 5-10C in temperature. I hadn't cleaned the dust out for nearly 2 years, when I noticed this much had built up.

---
\"... and if I close my mind in fear, please pry it open... \"

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Get rid of trapped dust so system runs cooler too!
Authored by: trevbucky on Mar 01, '07 07:17:07PM

Yeah I was amazed at the amount of dust in there. I cleaned it out darefully with a small nozzle attachment on my plastic handled vacume cleaner, then blew the rest out with compressed air. I too saw a 5 - 10 degrees change. After this & the fan swaps, my Powermac now runs at around 41 - 51 degrees celcius... and very quiet!



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Quieting a Mirrored Drive Door Power Mac G4
Authored by: ianeiloart on Feb 28, '07 10:55:23AM

300% quieter? I'd settle for 100%, but 300 would mean it was generating anti-sound!

Seriously, though. Apple offered a free fan replacement program, which I used. It's still quite loud. I did get to a point where it was absolutely ridiculous - until I discovered an air inlet at the base of the front panel. Cleaning the dust plug out of there made a huge difference. Now I keep the machine off the floor, and it doesn't gather so much dust.

Great tip, though. I might just look for one of those fans.

---
Ian Eiloart



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Quieting a Mirrored Drive Door Power Mac G4
Authored by: trevbucky on Mar 01, '07 07:12:59PM

Yes this machine was part of that power supply replacement, but still too noisy. I was amazed at the amount of dust near those vent holes too... clearing it cooled it down by 5 -10 degrees, but the noise factor was the problem, so I changed the fans.



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How about the iMac G5 rev. A?
Authored by: jctull on Feb 28, '07 11:29:19AM

Has anyone come up with a masterful fan replacement for the annoying cooling system in the rev. A iMac G5? The rev. B fixed it, but I believe they went with an entirely new power supply and internal configuration that makes it incompatible with the rev. A.



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How about the iMac G5 rev. A?
Authored by: trevbucky on Mar 29, '07 09:00:50PM

I'm afraid I cant help you there mate. The iMac is a pretty quiet machine anyway, my mate has a 1.8G5 iMac & it's very quiet. You would have to be very keen & skilled to tinker with that sort of modification to an imac.



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Quieting a Mirrored Drive Door Power Mac G4
Authored by: garythemacguy on Feb 28, '07 12:37:33PM

Thanks - you might just have given my MDD G4 a new lease of life as a (home) server when I upgrade it in (probably) a couple of months... I've long suspected the main fan, but just never got around to researching it. Now I'll not have any excuse! :-)



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Quieting a Mirrored Drive Door Power Mac G4
Authored by: trevbucky on Mar 13, '07 07:52:52AM

No worries, I was seriously considering getting rid of the Powermac & getting a iMac 24 inch until I did this quieting stuff to it as it was driving me crazy. Instead I picked up a 23 inch cinema display on ebay for a third of the price of an iMac 24 inch & ive got a much more upgradable & expandable machine which is still easily fast enough for me.



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Quieting a Mirrored Drive Door Power Mac G4
Authored by: Chas on Feb 28, '07 03:56:16PM

Apple issued an official noise fix for the MDD CPUs a long time ago. About a year or so after the machine was released, so many owners were griping about the noise that Apple set up a parts swap program. They shipped a replacement power supply (with quieter fans) and a replacement CPU cooling fan, all for the amazing cost of $25 shipping. You could install the kit yourself or take it to an Apple servicing dealer and they'd put it in for free. I installed it myself in my MDD and it was immediately quieter.
I doubt those kits are available any more, but it wouldn't hurt to check with Apple.



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Quieting a Mirrored Drive Door Power Mac G4
Authored by: trevbucky on Mar 02, '07 08:00:40PM

Yes I was told by the previous owner of my MDD Powermac ( a graphic design firm) that they did this apple fan swap & that it had made a big difference. I hate to think how loud it was beforehand. I was seriously thinking of selling it, but now it's whisper quiet so I think I'll keep it for a couple more years.



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Quieting a Mirrored Drive Door Power Mac G4
Authored by: richardjenkins on Mar 01, '07 09:13:52AM
Seconded! I have an MDD G4 Dual 1.25, and even after the Apple recall it was a noisy beast. I replaced the power supply fans with a kit from www.veraxfans.com and that halved the noise output.

It was still too noisy so I tried a couple of options but ended up with the same SilenX fan case fan as the original poster. It still makes a bit of noise on hot days, but doesn't make that awful ticking noise the others did. If I could find a way to isolate the fan body from the steel chassis I think I'd get a better result, but it's a bit cramped for that.

Looks like Verax don't do the kit any more and they are expensive, but they're the nicest fans I've ever used.

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Quieting a Mirrored Drive Door Power Mac G4
Authored by: trevbucky on Mar 05, '07 04:25:50PM

try putting a bit of padding under the main 120 mm fan too, this might stop some vibrations.



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Quieting a Mirrored Drive Door Power Mac G4
Authored by: g3ski on Mar 01, '07 11:50:14AM

90CFM to 18dBa ratio is awesome. I picked up a sub-20dBa fan that was supposed to be in the 75CFM range, but it wasn't cooling the CPU enough.

Nap mode has been know to be problematic on MDD towers - never worked on mine.

The fans in the powersupply are the worst offenders. They were rated around 55dBa to 45CFM, with stepping. It was actually difficult to find a worse ratio.
Replacing the fan within the power supply is a big undertaking, b/c you have to pull the whole computer apart, then dismantle the power supply, but it's worth it for a cheap solution.

---
"I want my two dollars!"



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Quieting a Mirrored Drive Door Power Mac G4
Authored by: trevbucky on Mar 06, '07 08:26:24PM
Yeah I tried a 72 CFM 120 mm fan first & this just didnt cool it enough. I havent had any problems with nap mode whatsoever! Have you tried upgrading to 10.4.3 or later? Earlier problems people were having as documented on this site below were on MDD macs running 10.3.x. Also I always use the Combo updaters.

http://www.xlr8yourmac.com/feedback/MDD_CHUD_feedback.html#storytop

Quote" Although one MDD owner initially reported problems after the 10.4.3 update with CHUD 3.5.2 Nap mode, he later said it seems ok now. 4 other MDD owners wrote they've seen no problems in 10.4.3 w/CHUD 3.5.2 NAP mode."

It's definitely worth doing the power supply fan replacement with the Thermaltake Vocano 5 Heatsink fans. I was a bit scared to do it as it all sounded too difficult, but if you get organised, take your time & do it carefully you should find it quite easy if you have some basic experience tinkering with electronics. Just follow the excellent instructions posted on this page:

http://www.xlr8yourmac.com/systems/g4_mirrored_drive_doors/noise_reduction/g4_ddr_noise_reduction.html




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Quieting a Mirrored Drive Door Power Mac G4
Authored by: michaelj on Mar 02, '07 10:46:24AM

Is the SilenX fan controlled by the thermostat like the original? I bought a replacement fan a while back which was supposed to be quieter than the original, but it ran at full speed all the time and ended up being noisier. BTW, I agree with richardjenkins - I got the verax kit for the PSU and it made a huge difference in the noise level. Pricey, but in my opinion well worth it. If the SilenX fan actually cycles up and down, then I need to get one ASAP!



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Quieting a Mirrored Drive Door Power Mac G4
Authored by: trevbucky on Mar 02, '07 08:08:34PM

Yes the silenx fan seems to cycle up and down, just like the original, and like another generic fan I tried which didnt put out enough air to keep it cool enough.
It's basicly silent mostly, then you can hear it spin up a bit more( still quiet) when doing any intensive tasks. I highly recommend it as it's a 5 minute job.



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Quieting a Mirrored Drive Door Power Mac G4
Authored by: trevbucky on Jul 21, '07 07:35:22AM

Further, it's important that you connect the Silenx fan to the 2 pin motherboard connector & not the 4 pin Molex connector. This way it cycles up & down in speed. With the molex connector it just remains on full speed, which is a bit too noisy.



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Quieting a Mirrored Drive Door Power Mac G4
Authored by: jvr on Sep 14, '07 12:31:51PM

I just bought the Silenx fan, but it has a 3-wire tail on it. How do I connect it to the 2-pin connector on the G4 MDD motherboard?



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Quieting a Mirrored Drive Door Power Mac G4
Authored by: lyd on Mar 03, '07 05:56:23PM

I did case and power supply fan replacements, insertion of a few bits of dense foam for isolating mechanical vibrations, and some simple airflow mods (to improve cooling efficiency with the lower rpm fans) with strategically placed cardboard years ago. It made my dual 1.25 much quieter, but by no means turned it into a "silent PC."

This past summer I was doing some recording using the MDD as my DAW platform, and the previous mods were not going to cut it.

I went back in and removed the perforated plastic panel on the rear, completely disconnected the small fan in the door that blows into the optical bays, and revamped the plenum completely using more cardboard and aluminum duct tape to seal all gaps and holes that interfered with smooth airflow through the case. Then I covered every surface -- sides, bottom, top and interior parts like the optical bays and sides of the psu -- with some dynamat (a very dense, self-adhesive vibration-damping material commonly used in car audio) that I had lying around. After reassembling it, I lined the corner where it sits with acoustical foam to further absorb any remaining high-frequency noise.

You can no longer tell it is running at all unless you are sitting right next to it, *censored* your ear and concentrate hard on listening for it. From 4 feet away you can not hear it at all. I can record spoken-word with a hot condenser mic ~10 feet away and have no problems. And all of that is in a completely silent room. With the heat or AC running, or normal house noise, you don't even know it is there when you are right on top of it.

lyd



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Quieting a Mirrored Drive Door Power Mac G4
Authored by: lyd on Mar 03, '07 06:02:56PM

I should add to the above the clarification that all the dynamat is on the inside surfaces of the case. The outside appears stock, except in the rear where I removed the useless plastic grating (leaving just the metal) to reduce flow restriction and noise from air turbulence.

lyd



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Quieting a Mirrored Drive Door Power Mac G4
Authored by: trevbucky on Mar 10, '07 02:30:05AM

Interesting... what does "revamped the plenum completely "actually mean? what is the Plenum?

Do you think you could take some pics of what you did & upload them somewhere for us to look at?



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Link is dead
Authored by: junk666 on Apr 05, '11 03:40:00AM

Link to download CHUD 3.5.2 is dead. Link to download CHUD 3.5.2 is dead. Link to download CHUD 3.5.2 is dead. Link to download CHUD 3.5.2 is dead. Link to download CHUD 3.5.2 is dead. Link to download CHUD 3.5.2 is dead. Link to download CHUD 3.5.2 is dead. Link to download CHUD 3.5.2 is dead. Link to download CHUD 3.5.2 is dead.



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