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CPU fan recommendations for dual 800 Quicksilver

It never rains but it pours.

Just a few hours after posting about HD heat issues my CPU fan has gotten really noisy with a slight rattling noise. Yes, it is the CPU fan. Maybe it's the hot weather we are having causing something to expand, or maybe the cleaning I gave it yesterday with compressed air pushed it over the edge. Anyway, I removed the fan, lubricated it with one drop 3M oil under the sticker, replaced it. All dust and dirt is off the blades. I have poked and prodded it to see if there were other items vibrating (e.g., the famous screws touching something), but nothing changes. The sporadic rattling (sometimes disappears for half a minute or so but usually there) really suggests to me that a bearing might be going. At this stage I think it is time to go shopping for a new fan.

This is a dual processor machine of the early QS series so it's like a toaster inside and I'm not sure if any of the standard QS fan recommendations apply to a dual. Of course I want everything - high CFM and silence. I found a lengthy discussion from last December talking about a single processor replacement but I thought I'd solicit current recommendations, especially for dual processor.

Thanks

G4 Quicksilver dual 800 MHz 2x120 GBHDs 1.5GBRAM dual-boot 10.4.11 9.2.2, 2 G3 beiges, IIci

Posted on Jul 16, 2008 9:25 PM

Reply
8 replies

Jul 17, 2008 8:18 AM in response to Limnos

"Just a few hours after posting about HD heat issues....."

That will teach you to complain about your Mac! They have feelings, too, you know.

Timely topic, too; dual CPU Quicksilvers have just come down in price on eBay to where they're reasonable for us terminally thrifty types.

For what it's worth, I acquired a dual 800 QS a few months ago; because of heat noise issues, its owner had replaced all its fans with new SilenX models. (Apparently, he didn't consider the result totally satisfactory, which was how I came to acquire it.) Running with the case open, I found the heat sink hot enough to grill bacon - far too hot to rest my hand on. (Specs on SilenX CPU fan: ixtrema "pro Series" quiet fan IXP34-16, 2000RPM 18CFM 16dBA)

Following a mention on the Forum here, I acquired a Sunon PMD1206PTB1-A CPU fan which fit neatly into the shroud. Specs are 36.0 CFM, 44.0 dBA, c.$12. As you may guess, it created considerable wind noise, but it cooled the Mac right down - I could rest my hand comfortably on top of the heat sink.

In the interest of comparison, I then plugged in a stock fan (Sunon KMD1206PTV1 - specs disappeared, but somewhere between the other two); the heat sink then became uncomfortably hot to the touch, but not to hot to rest my hand on. (It figured, I guess, but it's always nice to know these things operationally.)

Never did decide which direction to go, so I set it aside in favour of a single processor (933Mhz) QS which runs happily and just slightly warm.

Now I have acquired a bargain 1GHz QS, which again runs uncomfortably warm, but not too hot to touch - much as the dual 800 with the stock fan. One thing I notice is that the heat sink to the one side of the daughter card (over the second chip and out of line of the breeze of the fan) runs hotter than the side directly in line of the fan. It figures, of course, but (again) it's nice to know. I'm thinking now I may try the PMD wind tunnel next and see where it gets me.

I'm inclined to go with the wind tunnel for myself, but I sell these things to deserving members of the General Public (those with cash) and they tend to prefer quiet - even at the expense of reliability. Again, I'm inclined to think that a cool Mac is a happy Mac, but some things runs better when the heat is on, and perhaps the Forum community will recommend.

Jon

Jul 17, 2008 1:48 PM in response to Jon Smith

Thanks for the reply Jon.

I spent all morning running from computer store to computer store in this metro area with no luck.

Some places were the usual, "Oh, a Mac. Go buy one from them." Actually I did go to an Apple store but they don't have them in stock and I fear (from online prices) it would be pretty high ($50+) since they would get one from the Apple itself (kind of like going to a car dealership for new wiper blades).

One place actually gave me used Sunon KMD1206PTV1 (they didn't know if it actually worked). You're right, the online specifications are not to be found, and Sunon doesn't have them on the packages either. This one is rated at 12V, 2.2W which means a 0.18A power draw. My original fan has a 0.22A power draw. Power usually translates to CFM air flow so the Sunon isn't the same rating as the original fan and I'm concerned about using it in a dual processor. As you observed, you heatsink was pretty warm when using the Sunon KMD1206PTV1. Lots of places had Sunons new but they were all the same low power rating and they had molex connectors, or 3 pin.

The place that gave me the free fan also lubricated the old one with a thin grease. I reinstalled the old CPU fan (twice actually, since the first time I had it set to blow out, not in across the heatsink). It has quietened down a lot, though I regard this as breathing space to give me time to shop around online and still be able to use my only computer (my G3 is mothballed along with my IICi and not Internet capable anymore).

Jul 17, 2008 7:09 PM in response to Limnos

The specs aren't too hard to find; I just searched: " Sunon PMD1206PTB1". Google brought me to a Sunon site.

http://www.tmcscsi.com/Sunon.shtml

the above link doesn't seem to work as a link, but when I type it into my address bar, it works fine. Go figure!

which tells all. The KDE1206PTV1 fan is a different series and rated at 23.5cfm and 33.5 dBA, which I think we knew; it also runs somewhat slower and draws about half the current. More importantly, there are probably half a dozen 60X60X25mm fans of either the PMD or KDE series that would fit, and would push more or less air at more or less noise. What it doesn't tell is what your ear would call an acceptable compromise. In general, of course, more cfm, more dBA. It also doesn't tell how these stats compare to other brands; I ran it all down at one time, and it's a rather laborious process, but it can be done. I didn't have any frame of reference, so it was all just numbers to me; I set the whole matter aside until just now with your inquiry.

I wouldn't worry about the connectors too much; I fit QS fans to the DA model and wind up connecting them with Molex plugs and no problems. The replaced SilenX fan had three wires, of which only two were used, and it worked. Most PCs use a third wire to turn the fan off or on, or up and down, or something - which Apple doesn't. N.B. If you use the Molex connector, you will note that the red (5v) wire plugs into the yellow (12v) socket; not to worry - it spozed to. The PMD fan I got came with two wires, bared at the ends, but no connector(s). I wound up jury-rigging the connexion. PC accessory houses that sell fans also sell wire adapters of dozens of configurations, just search. My two favourite such houses are Xoxide.com and pcToys.com. I think I got the Sunon fan(s) from Allied Electric (alliedelec.com) for about $12 and $12 s&h, which is a minimum figure. You can ship multiple fans for that.

Sunon says its fans work on the Mag-Lev principle, so lubrication wouldn't help much. What would hurt would be an unbalanced fan, so it might help to clean the crud off the blades - evenly, if possible.

I keep wondering what a slot fan would do to cooling and noise, but that may be a thought better postponed. First should be getting the CPU acceptably cool. I also understand it helps cooling if you clip some of the grillwork in front of or behind the fans (power supply fans, especially).

Just a few thoughts ..... Jon

Jul 19, 2008 11:31 AM in response to Jon Smith

I'm still shopping around and think I might need to get something online. I called another brick and mortar place in my area this morning and got somebody who insisted upon only being able to supply me with a fan if she knew which model of Pentium PC I was running. :-P

[This Evercool|http://www.performance-pcs.com/catalog/index.php?main page=product_info&cPath=51&productsid=133 ] looks like a potentially good fan but might need [this adaptor|http://www.performance-pcs.com/catalog/index.php?main page=product_info&cPath=289&productsid=3596]. The fan has a 26.5CFM rating. I don't have the CFM rating for what's in my QS right now but my fan has a 0.22A power draw and the Evercool I calculate at 0.20A which is comparable. It has a 30dB noise rating which seems to be standard for something that CFM rating. The really quiet fans (20dB) all have much lower air flows which would concern me with a dual processor.

I like the idea of a higher CFM fan but the 40dB noise level is a pretty strong price to pay. It is a pity the these processors don't seem to have any way of reporting the temperature (I'd swear I recall my G3 being able to do that!) to see how effective the different fans really are. In [this discussion|http://discussions.apple.com/thread.jspa?threadID=1274033&start=25&t start=0] somebody reported getting extra cooling just by taping over the top of the heatsink to funnel the air through the vanes.

There was a [similar model at another web site|http://www.frozencpu.com/products/6650/fan-398/Aluminum 60mmFan.html?tl=g36c15s57] that was a few dollars less but I couldn't find any cable adapters on their site that match what I need, and by the time I pay shipping from two vendors I might as well just pay the few dollars extra at one place.

Do you have any experience with modifications? I have seen comments about placing tape over the slot at the top of the CPU fan housing. This seemed mainly to address noise issues but I was thinking it what might also be happening is it is just drawing air from inside the computer case which is already warm. If I closed the slot it might enhance air intake from outside the case which is cooler, though I am not sure if the fingerguard grating would allow for that. Any ideas? (And thanks for all your input, BTW.)

Jul 19, 2008 7:31 PM in response to Limnos

Hi guys-

I have followed Jon's model to some extent:
Look up the part number of the original fan to get the airflow in cfm (invariably the exact replacement is available only in the oh-so-handy 10,000-pack)
Find a page with lots of fans and look at their specs. This page works for these:
http://www.buyextras.com/60fanin25th.html

compare and contrast and see if you can converge on a desired airflow and other features with acceptable noise. This may also send you off to other sites looking for comparable fans or different brands with specific features.

For a reference point, 35 db is used as a typical \[large] office noise level.

RE: the yellow wire -
More than one site has referred to this wire as an RPM output, to be read by the CPU if your computer is set up that way. It can be safely ignored.

Jul 19, 2008 9:15 PM in response to Grant Bennet-Alder

Hi Grant.

Thanks for the information, especially that vendor who seems lower than the others. I looked online ([for example|http://www.mac-pro.com/Quicksilver-CPU-Fan-for-PowerMac-G4?sc=2&categor y=407]) and it appears that the general QS fan part number is Apple 922-4580 I can't seem to find anywhere that provides CFM specifications for that specific part. Probably they assume that all you really need to know is if you have the correct replacement. Unfortunately all the direct replacements are on the order of $30-$70+S&H, so I would much rather go with another model! However, the CFM rating appears to be linked to the power rating so that's why I figured I could go with one of similar or higher power rating.

This isn't a large office. It's a table in the corner of a room with the CPU fan 24" from my left ear. My only alternative is to place it on the floor under the table but then it would act as a cat hair vacuum cleaner. After reviewing fans on websites I can't seem to find anything with sufficient CFM rating that is substantially quieter than 30-35dB so I think I'll have to live with it. Although 35dB may be large office noise that's just the CPU fan alone. There's another two (maybe PCI slot fan to come) fans in the machine as well as two hard drives.

CPU fan recommendations for dual 800 Quicksilver

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