Apple G5 2.5 - Liquid cooled or heatpipe? EDIT: *** CONFIRMED *** - It IS Liquid Cooling

[Eug]

From this thread: http://forums.anandtech.com/messageview.cfm?catid=27&threadid=1327464&STARTPAGE=2&enterthread=y

Apple released new G5 2.5 GHz dual Power Macs yesterday. http://www.apple.com/powermac/

So Apple describes an OS-controlled liquid cooled system with 21 sensors, using water with propylene glycol. They also have had dealings over the past couple of years with http://www.cooligy.com/ who makes pumps with no moving parts.

Do you think Apple is just using a high-end heatpipe, or do they have some uber-cool true liquid cooling system?

EDIT:

Picture of cooling assembly. It IS real liquid cooling.

Link

The LCS cooling system fluid is predominantly water (80% or greater) with a mixture of corrosion inhibitors, antifreeze, and bacterial growth preventatives.

...So if your office air-conditioning system goes berserk you won't have to worry about your processors exploding...

Of other interest, "Nitrile or rubber glove should be worn when handling an LCS module that is leaking or suspected to be leaking. Evidence of leaks would include corrosion around fittings in the LCS coolant system, a light green or red liquid present, or a slick or slimy feel when handling the part. For leaks or spills, wipe up the fluid using rags, paper towels, or other suitable materials. Dispose of all cleaning materials according to local laws and regulations (Refer to laws and regulations pertaining to disposal of Antifreeze). Do not combine used coolant with any other chemical.

Place the failed LCS module (leaking or not) in the packaging that the replacement module came in. Follow the packaging instructions included with the replacement module. Failure to follow the instructions could damage your equipment and void warranty coverage."

 

[arcas]

I've never heard of the Cooligy electrokinetic pumps before. Why haven't these caught on? Licensing issues?

 

[Eug]

Originally posted by: arcas
I've never heard of the Cooligy electrokinetic pumps before. Why haven't these caught on? Licensing issues?

Cost? And yeah I'm sure Cooligy has patented everything up the yinyang so anybody using would have to licence it from Cooligy.

 

[sparkyclarky]

Originally posted by: Eug

Originally posted by: arcas
I've never heard of the Cooligy electrokinetic pumps before. Why haven't these caught on? Licensing issues?

Cost? And yeah I'm sure Cooligy has patented everything up the yinyang so anybody using would have to licence it from Cooligy.

Most likely performance too - while these pumps may be suitable for OEM use, watercoolers tend to demand a bit more from a pump

 

[oldman420]

they are using heat pipe technology and using the case itself as a radiator there is no noise from and mechanicle parts in that case very cool i want one "and i dont realy like macs"

 

[0roo0roo]

.

 

[Eug]

Well, a couple things make me think it may be some sort of real liquid cooling.

1) Article from ComputerWorld

Apple is using a closed-loop liquid cooling system comprised mostly of water with some propylene glycol, Boger said. It is transparent to the user and maintenance-free, he said.

2) It says it's a loop. I thought heatpipes are just pipes, not a circuit, no?

3) Previous G5s and G4s and Mac laptops, etc. all already use heatpipes, but Apple has never advertised this before.

4) Article from October 2003

The cooling system can handle 1,000 watts per square centimeter, the company claims. Passive cooling systems can cool only 250 watts per square centimeter, according to the company.

The technology was originally developed at Stanford under Darpa's Heretic program, an effort to develop solid-state, heat-dissipation devices for microelectronics and photonics.

Apple Computer, Advanced Micro Devices and Intel also cooperated, the company said. "The Intel test produced the highest performance Intel had ever seen from any cooling technology," Cooligy said.

5) Article from IT World

The new 970FX processor is much smaller than its 0.13-micron predecessor, which means the heat from the CPU (central processing unit) is more concentrated, said Tom Boger, senior director of product marketing for Apple. The new chip is consuming roughly the same amount of power as the older chip, and a more sophisticated system is needed to remove the heat from the processor die.

So basically, Apple specifically says that total heat output by the new chip has NOT increased, but the wattage per unit area has increased (because it's a smaller area), making traditional air cooling less desirable. Systems like Cooligy's specifically address this issue. Furthermore, Cooligy was already working with Apple way back in 2003 or perhaps even earlier.

Originally posted by sparkyclarky:
Most likely performance too - while these pumps may be suitable for OEM use, watercoolers tend to demand a bit more from a pump

Are you talking about overclockers?

Originally posted by: oldman420
they are using heat pipe technology and using the case itself as a radiator there is no noise from and mechanicle parts in that case very cool i want one "and i dont realy like macs"

I don't think they're using the case as a radiator. They still have lots of fans too. The front has a grill with lots of holes, and the back has large fan ports.

 

[Gravity]

Ordered one this week. I'll let you know.

 

[Eug]

Yep, power density is the problem.

The new model also features an all-new liquid cooling system, necessitated, according to Apple, by the switch to the new 90 nm process, which reduces the chip size dramatically from the previous G5 design.

"When that happens, you face what we call a 'power density challenge,' where what you need to do is pull heat from that part more efficiently than what we were able to do with a traditional copper heat sink. That cooling system does that, it does that quite efficiently, does it very quietly. It's a maintenance-free, closed-loop system. The customer never has to think about it."

 

[Eug]

Real life pic of cooling system.

It's got heatpipes, but it's got true liquid cooling too. (BTW, it's not Cooligy though.)

Link

The LCS cooling system fluid is predominantly water (80% or greater) with a mixture of corrosion inhibitors, antifreeze, and bacterial growth preventatives.

...So if your office air-conditioning system goes berserk you won't have to worry about your processors exploding...

Of other interest, "Nitrile or rubber glove should be worn when handling an LCS module that is leaking or suspected to be leaking. Evidence of leaks would include corrosion around fittings in the LCS coolant system, a light green or red liquid present, or a slick or slimy feel when handling the part. For leaks or spills, wipe up the fluid using rags, paper towels, or other suitable materials. Dispose of all cleaning materials according to local laws and regulations (Refer to laws and regulations pertaining to disposal of Antifreeze). Do not combine used coolant with any other chemical.

Place the failed LCS module (leaking or not) in the packaging that the replacement module came in. Follow the packaging instructions included with the replacement module. Failure to follow the instructions could damage your equipment and void warranty coverage."

 

[ViRGE]

Originally posted by: Eug
3) Previous G5s and G4s and Mac laptops, etc. all already use heatpipes, but Apple has never advertised this before.

Wait, my AlBook has a heatpipe in it? Wow, I never would have expected that.:Q

 

[0roo0roo]

good info eug🙂

 

[Eug]

Hmmm... Judging by the pics, there are lots of rubber hoses. I hope that leaks don't become a problem.

Originally posted by: ViRGE

Originally posted by: Eug
3) Previous G5s and G4s and Mac laptops, etc. all already use heatpipes, but Apple has never advertised this before.

Wait, my AlBook has a heatpipe in it? Wow, I never would have expected that.:Q

12" AluBook disassembled. (Several pages long - a few pictures include the heatpipes.)

 

[ViRGE]

Originally posted by: Eug
Hmmm... Judging by the pics, there are lots of rubber hoses. I hope that leaks don't become a problem.

Originally posted by: ViRGE

Originally posted by: Eug
3) Previous G5s and G4s and Mac laptops, etc. all already use heatpipes, but Apple has never advertised this before.

Wait, my AlBook has a heatpipe in it? Wow, I never would have expected that.:Q

12" AluBook disassembled. (Several pages long - a few pictures include the heatpipes.)

You even remembered what PB I had; I'm flattered.😛

 

[Eug]

Diagrams of cooling system:


:camera: #1

1. G5 processor at point of contact to the heatsink.
2. G5 processor card from IBM
3. Heatsink (also referred to as a 'waterblock')
4. Cooling fluid output from the radiator to the pump
5. Liquid cooling system pump
6. Pump power cable (usually connected to the main logic board, but repositioned in the above diagram)
7. Cooling fluid radiator input from the G5 processor
8. Radiant grille
9. Airflow direction

:camera: #2

1. Liquid cooling system pump
2. G5 processors
3. Radiator output
4. Radiator
5. Pump power cable
6. Radiator input

 

[Gravity]

Could this be the way all cases are cooled one day?

 

[Eug]

Real life pics of the G5 cooling system.