Air Cooled Yikes! PowerMac G4

The G4 was the first machine I tried to silence. Computer noise winds me up and with a few inexpensive mods, I was able to bring down the volume of the Mac by a huge amount.

It was mildly modified machine to start with. The CPU was overclocked from 350 to 400Mhz and eventually swapped for a 500Mhz processor. The graphics went from ATi Rage 128 to a Voodoo 5 finally settling on a ATi Radeon. A faster IDE controller running a pair of Western Digital hard disk drives later replaced with an almost silent Samsung drive and finally sold with an IBM.

For the silencing I started with Akasa matting. The idea behind this is that it cuts down high frequency fan and HDD noise. Next came the fans. In the Yikes! PowerMac there is a 120mm system fan that blows across the CPU and PCI slots, a 80mm PSU fan and the fan on the Radeon. Most painful of these by far was the Radeon cooler. It was so bad in fact that I ran with the fan simply disconnected for a long time. This was fine with the 120mm blowing on it, but I planned to undervolt that so I thought it'd be a good idea to fit a decent passive cooler to the GPU. Zalman offered a solution in the form of the ZM-17CU copper cooler.

Using the special heat sink extraction tool (a knife...), I very carefully removed the old fan and replaced it with the Zalman cooler. Sadly this obstructs the next PCI slot but it runs so cool that it's worth it.

With the cooler on the Radeon doing it's thing and the very cool nature of a late revision G4/500 CPU, I fitted a resitor in line on the 120mm system fan to bring it down to 7v. Both the CPU and GPU still only remained warm to the touch after giving the machine a prolonged heavy load so all was well. Noise was reduced dramatically.

This left only the PSU fan to deal with. Given the fact that this machine had been used very heavily for the last four years, it was not a surprise to find that the bearings were on their way out. Taking that as an excuse to fit a better fan I replaced it with an 80mm Zalman ZM-F1. The fan in the Yikes! PSU is speed controlled anyway so it was a simple job to swap out.

By this stage I'd become fairly obsessed with getting the machine as quiet as possible (very addictive this) and the twin Western Digital hard disks were driving me insane. Rated at 41db each, they just had to go. So out they came and in went a Samsung SP0802N Spinpoint P80 ATA/100 drive rated at 27db. Seagates are quieter at 25db but didn't offer the 3 year warranty that Samsung do, which is what swung it for me.

The resulting machine was dramatically quieter. So I sold it and replaced it with the noisiest Mac Apple had ever made. This was going to take a little more effort to deal with!

[ back ]