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mediahound · Sep 27, 2005, 08:46 AM

Is the Dual 2.3 liquid cooled? If no, I guess this site is incorrect:

http://www.g5drivebracket.com/description.php

OreoCookie · Sep 27, 2005, 09:28 AM

Bandit240 · Sep 27, 2005, 12:20 PM

Somehow i dont think i would want a watercooled computer. A buddy of mine had a PC that was watercooled and one of the hoses inside came loose. What a mess.

mediahound · Sep 27, 2005, 12:25 PM

The liquid cooled G5s are totally sealed, I've never once heard of a hose coming loose or anything. That said, I bought the highest one without liquid cooling (dual 2.3) because the liquid cooling does add some noise to the box.

OreoCookie · Sep 27, 2005, 12:50 PM

Originally Posted by Bandit240

Somehow i dont think i would want a watercooled computer. A buddy of mine had a PC that was watercooled and one of the hoses inside came loose. What a mess.

Your buddy was cheap. He should have used self-sealing connectors. If you know how to do it, it's a piece of cake and pretty much as safe as an air-cooled system. Especially industrially-produced water coolers are safe. Doesn't mean, they're cheap, though

Big Mac · Sep 27, 2005, 12:53 PM

I only believe in buying naturally cooled G5s, but if there were a super deal on a 2.5/2.7 or someone dropped one in my lap I wouldn't complain. Well, I would complain if it were literally dropped in my lap, but. . .

OreoCookie · Sep 27, 2005, 12:59 PM

Originally Posted by mediahound

The liquid cooled G5s are totally sealed, I've never once heard of a hose coming loose or anything. That said, I bought the highest one without liquid cooling (dual 2.3) because the liquid cooling does add some noise to the box.

Can I ask you something? You posted a thread, asking whether your system's cpus have a liquid cooling system, and now you say, you wanted one without liquid cooling system, and that's why you bought the 2.3 GHz model??

Liquid cooling is more silent, but obviously only at the same clock speed.

Todd Madson · Sep 27, 2005, 03:03 PM

The 2.5 and 2.7 models with liquid cooling STILL have NINE fans capable of a hell of a lot of noise
should they be needed.

Most of the time I can hardly tell it's on but when the fans kick in, believe it, it's noticeable.

OreoCookie · Sep 27, 2005, 03:30 PM

The only thing liquid cooling adds noise-wise is the pump. Pumps run at low rpms, so they add very little to the total noise output. However, all liquid cooling does is to transport heat from A to B very efficiently. You still need to transport it from the surface of the radiator via regular fans. In the PC world, radiators are sized such that they can be cooled by two 120 mm fans which you can set to low rpms (usually people don't bother and just use the 5 V line).

rogerkylin · Sep 29, 2005, 07:22 PM

Originally Posted by OreoCookie

The only thing liquid cooling adds noise-wise is the pump. Pumps run at low rpms, so they add very little to the total noise output. However, all liquid cooling does is to transport heat from A to B very efficiently. You still need to transport it from the surface of the radiator via regular fans. In the PC world, radiators are sized such that they can be cooled by two 120 mm fans which you can set to low rpms (usually people don't bother and just use the 5 V line).

If I'm not mistaken, the water cooling was actually used so the fans could run more slowly, giving an overall quieter box.

OreoCookie · Sep 29, 2005, 09:47 PM

Originally Posted by rogerkylin

If I'm not mistaken, the water cooling was actually used so the fans could run more slowly, giving an overall quieter box.

No, but the heat is transported much quicker, but 1 W of heat is 1 W of heat, no matter how you get rid of it. Most radiators have a larger surface area and you can have a larger fan running at lower rpms. In case of my brother, his radiator is twice the size of that of a G5s per cpu (so all in all, they are the same size for both cpus).

The other reason you can reduce the rpms of your fans is that you have less hot spots, as water distributes heat more quickly.

mediahound · Sep 30, 2005, 12:02 AM

but the liquid cooled G5 fans don't run slower than the non liquid cooled ones do they? All G5 fans run slow by default (unless they start heating up and then the circuitry speeds them up temporarily to cool things down).

the ones that require liquid cooling (ie. 2.5Ghz and 2.7Ghz) run so much hotter that they need the liquid cooling in order to be able to not heat up and run at the equivalent normal temps. but the fans run the same speed.

the liquid cooled ones are noisier probably due to the water pump.

If I'm not mistaken, the water cooling was actually used so the fans could run more slowly, giving an overall quieter box.

OreoCookie · Sep 30, 2005, 03:58 AM

Originally Posted by mediahound

the liquid cooled ones are noisier probably due to the water pump.

I don't think you'll be able to hear the pump at all. It runs at low rpms and the noise is completely masked by other sources of noise.

voo · Sep 30, 2005, 04:30 AM

Yup its only the grey fans themself you here nothing else. That trully is the loudest part of the system once they really kick in.

mediahound · Sep 30, 2005, 12:36 PM

the question then becomes, do the fans kick in (ie spin faster) on the 2.5 and 2.7 machines? because i've heard that the 2.5 and 2.7 G5s are louder. so if that's true, then i would venture to guess that the fans on these liquid cooled models must kick in more often because the liquid cooling is not enough to keep them as cool.

OreoCookie · 01:06 PM

Read my first reply. The liquid cooling system only transports the heat faster and more reliably to the radiator. No cooling system can do more than that. If the cpu produces – say – 80 W, then those 80 W have to be transported out of the system one way or another. So `liquid cooling is not enough' is a physically incorrect statement as no cooling system reduces the heat emitted by the cpu.

So in this sense, the only difference in noise you will be able to perceive is because a Dual 2.7 G5 system emits more heat than a Dual 2.3 GHz G5. Assuming Apple did not tweak the voltage (which I find unlikely), the power scales linearly in frequency (and quadratic in voltage), then a dual 2.7 GHz system's cooling system has to cope with at least 18 % more heat, but probably more.

voo · Oct 1, 2005, 02:42 AM

Originally Posted by mediahound

the question then becomes, do the fans kick in (ie spin faster) on the 2.5 and 2.7 machines? because i've heard that the 2.5 and 2.7 G5s are louder. so if that's true, then i would venture to guess that the fans on these liquid cooled models must kick in more often because the liquid cooling is not enough to keep them as cool.

Yes its louder and kicks in alot depends on the load but usually dealing with images like in Safari any image that you see alot on screen you hear it rev up it makes the 6800 sound quiet. But any other time it is whisper quiet I always forget the G5 is on as I can't hear it for the PC thank goodness for those little white lights.

You could compare the watercooling to a car, still has a radiator a pump and a large fan that spins up and down on its load too.