I think liquid cooling is much better than simple air cooling.
I already have liquid cooling kit lying around here for my hackinstosh.

Swapped over the LCS to passive cooling. Typing on it right now. It's runningat 81*C at the moment. I will keep an eye on it and see where it peaks out.

The LCS had no visible signs of leakage until I removed the CPU cards from the LCS. Sure enough, there was leakage around the screws at the thermal plates. There was very minimal area that was on one CPU card, the other was clean. I guess I got lucky.

[ Edited by SteveE617 20.06.2013 - 18:59 ]

Passive and at 81c, that sounds good for these machines.
Well, I will try to get some heatsinks.
I have the 2.5ghz DP system.
Do I need a specific heatsink? From the 2ghz model?

I used the heat sinks from a 2.0Ghz, PCI-X machine. They don't look any different from the 2.0Ghz, PCI machine I have.

The only diiference between the coolers located on the CPU boards themselves is the passive cooler on the 2.5 boards are taller than those on the 2.0 boards. They still work, just a little taller.

I don't believe, that you are passively cooling a G5 processor.
It will blow the cpu.

Doffo has been running a passive cooled machine for a little while now and it seems to be running OK, It may eventually blow up the CPU, but hasn't yet....what's not to believe? Do I need to take pictures?

Quote:

By 'passive cooled' do you mean heat-sinks only?

Quote:

Yes, running the heatsinks, but obviously the fans are still intact.

I did not like the fact the fans spooling up as soon as it gets passed 87C, but they do spin back down shortly after it brings the temp down to 84c. Even with a 120mm connected to the 12v molex blowing air across the heatsinks, it kept it under 85C the whole time.

If they blow up, let them. Have a spare 2.7 g5 tower along with some xserve 2.3ghz cpus I have to try outl. My G5 tower is still running. After I replace all 4 fans so they are always on, I hope to see temps drop much lower. I will report back once everything comes in.

Anyone got a set of heatinks to fit my 2.5ghz DP G5 they can ship me?

Passive cooling certainly means heat sinks only, no fans and
pictures would be very helpful to believe that.

[ Edited by Tom01 22.06.2013 - 21:48 ]

Any way to make the fans run 24/7?

Quote:

Well of course there's fans in it. The machine basically looks like a non-liquid cooled G5, except the voltage regulator heat sinks sit even with the 2.0 cooling radiators. Loo at the link I posted at the beginning of this thread, you'll see what it looks like.

If anyone thinks that you could remove the fans from the system and rely entirely on the radiators without moving any air is absolutely absurd!

>> Passive cooling certainly means heat sinks only, no fans

> of course there's fans in it.

So it's in fact active air cooling, not passive cooling.

"The term "passive" implies that energy-consuming mechanical components like pumps and fans are not used."
http://en.wikipedia.org/wiki/Passive_cooling#Passive_cooling

I'm not sure why you, pampers, Doffo and bash64 seem to think that air cooling is a type of passive cooling.

> Any way to make the fans run 24/7?

Just leave the machine running 24/7 :-)

I simply did not dispute the 'passive cooling' term since it appeared to be a Mac term and I am not a Mac person.

However, I would NEVER run heatsinks without fans, especially on a machine that likes to stay at 80c and above.

> I simply did not dispute the 'passive cooling' term since it appeared to be a Mac term

Does that mean Mac people are defining this term differently from the rest of the world? Wouldn't be too suprising ;-)

> I would NEVER run heatsinks without fans

Worked well on my Pegasos I :-)

Ah, YES, Mac people are a bit wierd.
Why does one pay up to $3000 for a laptop made of plastic?
Must be a Mac thing or a Steve Jobs worship kinda thing.

Quote:

Exactly..Active Cooling, Not passive...my mistake.

Ah, so it is fan cooled then.

I was amazed that it could have been passive cooled like a G3! :)

>>> I simply did not dispute the 'passive cooling' term since it appeared to be a Mac term

>> Does that mean Mac people are defining this term differently from the rest of the world?
>> Wouldn't be too suprising ;-)

> YES, Mac people are a bit wierd.

But obviously not as weird as confusing air cooling for passive cooling ;-)

>> I'm not sure why you, pampers, Doffo and bash64 seem to think that air cooling
>> is a type of passive cooling.

> Exactly..Active Cooling, Not passive...my mistake.

Thanks for clarification. However, "LCS --> Active Cooling" is still confusing, as liquid cooling is a type of active cooling as well. So it should be "LCS --> Air Cooling" instead.

My mistake! :P :P Guess it was "Active" cooling this whole time! I might have to rewrite that guide sometime so it don't throw people off.

At the time of writing this all my cables/fans came in. I am working on it and I will hopefully have results later.

Everything installed great!

Even under load I was seeing temps around 72C. I highly recommend to just replace all 4 fans with the molex connector and call it the day if you decide to convert to some heatsinks. I bought my fans/molex fan connectors from the following fleabay links:

Molex to fan connectorsFans

I did went the extra step of adding a drop of machine oil to the bearings, but this was just for the life of the fans. They appeared to be pretty well lubricated from the factory.

Best part was that it did not sound like a jet engine taking off. Fan noise is noticeable but not extremely loud. I will sacrifice some dB just to give these 2.7s some extra life.

Thanks, I love it when people share the link to buy the correct parts.
I just bought both the molex connectors and the 4 fans.

I am negotiating the heatsinks and should get them soon also.
72c sounds really good for these machines.

When removing the older fans, dont be shy to pull each corner of the fan so it slides off the rubber mount. You can reuse these mounts for the new fans once they come in. The only ones that were difficult to fully get on were for the exhaust side inner rubber mounts. I used a needle nose pliers to pull on the mounts as much as I could and that was it. Ill take some better pictures since the ones I took last night were difficult to see.