• Hello, Guest! Welcome back, and be sure to check out this post for more info about the recent service interruption and migration.

G4 Cube Cooling


New member
Hey kinda weird question but thought I'd ask here before pulling my Cube apart....

I have a NewerTech dual 1.8ghz CPU card that should work in the cube motherboard from my research.... But obviously cooling is an issue..

So my question is has anyone removed the cube heatsink and replaced it with active cooling? I have replaced the fans in the CPU upgrade so was planning to use that with its factory heatsink and maybe add another one in front.

Is the cube heatsink structural or I free to rip it out and try this?

This is the upgrade in case anyone is curious...



Well-known member
Welcome shapenz,

Nice upgrade, in theory the CPU is supported in the Cube, but with much higher power and cooling requirements that you've already noted. The G4 Cube cooling works on convection and heavily dependant on that large heatsink which acts also as an internal skeleton to support other components. Removing all of this and adding the pictured, feeble OEM NewerTech heatsink will probably make it overheat in the stock enclosure (you could consider making another enclosure to improve cooling).

The existing Cube 450/500Mhz G4 CPU has a large flat heatsink that sits below the larger convection heatsink - others have fabricated replacement (copper) heatsinks, but be careful of not applying too much pressure to cause CPU core damage. You can install a full size 80mm fan in the base with some gentle prying of the frame. Also consider you'll need an upgraded VRM for this upgrade, Artmix Stratos the only available option and it is not guaranteed to work with all CPU upgrades.
Last edited:


Well-known member
The Cube heatsink is somewhat structural. The closest I've seen to what you describe is where part of the heatsink was cut out to do an upgrade similar to what you plan:

Is your CPU 7447 or 7448? The '47 usually requires more power for the same speed and is thus harder to keep cool.
Most people just add fan(s) to the Cube.
If you're not already aware, I would suggest researching the VRM limitations when it comes to Cube upgrades.

Good luck with your project and keep us posted!


Well-known member
The official Sonnet Cube upgrades came with a fan, a low-profile type about half the thickness of a normal PC fan (I think it's 80x25mm). It bolts to the stock fan mounts on the bottom of the case and plugs into the stock fan power on the VRM (the Cube was intended to have a fan but of course Steve hated fans so it was deleted for production models). I put in a fan on my own because I didn't get the official Sonnet upgrade and I ended up tapping power from the hard drive's Molex plug with one of the typical PC fan splitters. The fan's relatively loud but it keeps things cool.