Go Back   MacRumors Forums > Apple Hardware > PowerPC Macs

Thread Tools Search this Thread Display Modes
Old Feb 8, 2011, 10:55 AM   #1
macrumors 6502
Join Date: Aug 2007
Custom Heatpipe to hack an imac G4 with x86 motherboard?

This may be a stupid idea...

There have been many methods discussed about squeezing a modern computer into an imac G4. None have been 'perfect' and compromises have always been made. Space is the biggest problem.

What if the imac's existing cooling system was kept intact? All we would need is to make a custom heatpipe that transfers heat from the new CPU (on a small motherboard) to the heatsink plates on the top part of the dome.

As a rough guide, I've checked the thermal output on this page - a 2.66ghz core2duo system has the same BTU under load and a cooler BTU at idle as a G4 1.25ghz. So I reckon the existing cooling system could handle the new chip.

Making a single part would be quite expensive. Maybe if there was enough interest, several could be produced to save money.

After that, there is the issue of power supply, routing the ports and converting the video signal. All of that has already been done (I think the video conversion only worked with the newer imac G4 models).
pubjoe is offline   0 Reply With Quote
Old Feb 8, 2011, 11:25 AM   #2
macrumors 68030
Join Date: Nov 2008
Location: UK
You can buy straight heatpipes (don't ask me where, I looked into that about a decade ago ). All you'd need then is a pipe bender for small diameters and a CNC for manufacturing a custom heat sink.

That sounds easy, isn't achievable for the majority of individuals, though.
That being said, I'd rather place a small active cooler on the CPU, without fiddling around heatpipes and such. Cheaper and given the TDP of a Core2Duo probably doable.
Transporteur is offline   0 Reply With Quote
Old Feb 8, 2011, 01:07 PM   #3
Thread Starter
macrumors 6502
Join Date: Aug 2007
Thanks. It at least sounds do-able.

The trouble with using a small cooler directly on the CPU is that even if you could fit one in only about an inch of clearance under the optical drive, it would be so cramped that I don't think it would move any air. On top of that, if you could somehow use tiny side-mounted fans to move air horizontally, I don't think the warm air would exit the dome case sufficiently.

...If it could be made to work it would be a lot easier though.
pubjoe is offline   0 Reply With Quote
Old Feb 9, 2011, 06:32 AM   #4
macrumors 68030
fhall1's Avatar
Join Date: Dec 2007
Location: NY State of mind
The hard part's going to be connecting video off the PC motherboard to the iMac LCD and getting it to work.
2012 2.3GHz i7 Mini, 16GB RAM; 2009 2.93 GHz C2D iMac, 8GB RAM, GT120 GPU
1.83 GHz CD Mini, 2GB RAM, 200GB HD; 1.25 GHz 17" G4 iMac, 2GB RAM, 128GB SSD
64GB Silver iPhone 5s, 64GB White iPad Air
fhall1 is offline   0 Reply With Quote
Old Feb 9, 2011, 10:24 AM   #5
Thread Starter
macrumors 6502
Join Date: Aug 2007
I'm pretty sure the newer model imac G4 screens can be adapted to dvi. I'm on my phone right now so it's difficult to look up the information, but I know that this has been a greatly discussed long term problem which someone has recently written a detailed solution and supplied pinout diagrams for. ...Brightness control was sacrificed though.

I'm sorry I'm not giving credit to the person right now.
pubjoe is offline   0 Reply With Quote

MacRumors Forums > Apple Hardware > PowerPC Macs

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Similar Threads
thread Thread Starter Forum Replies Last Post
HD4000 driver hack for custom VRAM size kpkp OS X 10.8 Mountain Lion 95 May 17, 2015 04:57 AM
iMac G5 20' motherboard info - fried component, need code from it erve34axim iMac 0 Aug 22, 2013 05:08 PM
Wondering if I can also hack HD3000 to have a custom VRam size vista980622 OS X 10.8 Mountain Lion 1 May 4, 2013 04:25 PM
Surface RT Hack to allow installation of x86 Desktop Applications TheHateMachine Alternatives to iOS and iOS Devices 8 Jan 12, 2013 02:18 AM
New motherboard inside iMac G3 Ruby Graveyard PowerPC Macs 2 Dec 10, 2012 02:42 AM

Forum Jump

All times are GMT -5. The time now is 07:41 PM.

Mac Rumors | Mac | iPhone | iPhone Game Reviews | iPhone Apps

Mobile Version | Fixed | Fluid | Fluid HD
Copyright 2002-2015, MacRumors.com, LLC