Power Mac G4 cooling project: Phase 2 - The baseline

It is finally time to kick this project off, so lets go! I will get some preliminary information out of the way first.

The temperature in my room is 80°F/27°C.

My Radeon 9800 Pro has a fresh thermal paste job using Arctic Silver 5.

My Motorola G4 1.33GHz 7455B has a fresh thermal paste job using Cooler Master High Performance Thermal Compound (HTK-002).

My memory sticks have heat spreaders on them.

Before I get creative and start moving fans around and swapping them out I need to get a set of baseline temperatures. I will be using the stock fans in their original locations and orientations. I will use the resulting baseline as a metric to determine the success of all the future cooling modifications during this project. Dan (PPCLuddite) suggested using CHUD in OS X for nap mode and powernowd in Debian for CPU frequency scaling. These should obviously help bring the temperatures down so I would like to test them out. Unfortunately I have hit a snag. I am unable to get powernowd working on my Quicksilver. I fear that my CPU is not compatible with powernowd. When I run powernowd as root I get the following results...

powernowd: PowerNow Daemon v1.00, (c) 2003-2008 John Clemens
powernowd: Found 1 scalable unit: -- 1 'CPU' per scalable unit
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq: No such file or directory

For grins I ran the same command on my iBook G3 as its CPU does scale with powernowd. Here are it's results...

powernowd: PowerNow Daemon v1.00, (c) 2003-2008 John Clemens
powernowd: Found 1 scalable unit: -- 1 'CPU' per scalable unit
powernowd: cpu0: 400Mhz - 700Mhz (2 steps)

I do not have an original Quicksilver CPU so I am currently unable to test against that fear. After running dmesg I found the following encouraging line.

[ 0.000000] Processor NAP mode on idle enabled.

Even though I cannot currently get my CPU to scale with powernowd on my Quicksilver, at least I have nap mode in both Debian and OSX. I feel like I have talked enough, lets get onto the tests and results, shall we?

Ten minutes of idle. OS X 10.4.11. CHUD nap mode disabled:
CPU: 57°C
GPU: 43°C
RAM: 43°C
Intake air: 38°C
Exhaust air: 33°C

Ten minutes of idle. OS X 10.4.11. CHUD nap mode enabled:
CPU: 42°C
GPU: 42°C
RAM: 39°C
Intake air: 34°C
Exhaust air: 33°C

Ten minutes of idle. Debian Wheezy:
CPU: 42°C
GPU: 42°C
RAM: 42°C
Intake air: 34°C
Exhaust air: 34°C

My first stress test will be web browsing. I will have three tabs open, PowerPC Liberation, FrozenCPU.com and Newegg. During the test I will flip between FrozenCPU and Newegg, browsing both sites for fans.

Surfing under TenFourFox 31. OS X 10.4.11:
CPU: 51°C
GPU: 43°C
RAM: 43°C
Intake air: 38°C
Exhaust air: 34°C

Surfing under Ice Weasel 24.7.0. Debian Wheezy:
CPU: 51°C
GPU: 43°C
RAM: 43°C
Intake air: 38°C
Exhaust air: 34°C

Now for my second test. I will rip a portion of a DVD using handbrake under OS X. I will be using Handbrake 0.9.1. My codec choice will be XviD. My average bitrate choice will be 2000kbps. I will be using 2-pass encoding and the AVI container. These settings came from Zen's excellent XviD guide. I recommend reading it if you haven't already.

The DVD rip results are...
CPU: 61°C
GPU: 46°C
RAM: 48°C
Intake air: 42°C
Exhaust air: 36°C

The third test will be the playback of the resulting AVI file. I will use VLC under OS X and Debian. In addition to VLC, I will test mplayer in Debian.

OS X 10.4.11 VLC 0.9.10 full screen playback:
CPU: 43°C
GPU: 39°C
RAM: 39°C
Intake air: 34°C
Exhaust air: 33°C

OS X 10.4.11 VLC 0.9.10 windowed playback:
CPU: 43°C
GPU: 42°C
RAM: 41°C
Intake air: 34°C
Exhaust air: 33°C

Debian Wheezy VLC 2.0.3 full screen playback:
CPU: 46°C
GPU: 43°C
RAM: 42°C
Intake air: 36°C
Exhaust air: 34°C

Debian Wheezy VLC 2.0.3 windowed playback:
CPU: 46°C
GPU: 43°C
RAM: 42°C
Intake air: 38°C
Exhaust air: 34°C

Debian Wheezy mplayer svn34540 full screen playback:
CPU: 46°C
GPU: 43°C
RAM: 43°C
Intake air: 36°C
Exhaust air: 34°C

Debian Wheezy mplayer svn34540 windowed playback:
CPU: 46°C
GPU: 43°C
RAM: 42°C
Intake air: 38°C
Exhaust air: 34°C

This experiment needs more first person shooters. Time for some Quake III Arena!

Quake III Arena OS X 10.4.11:
CPU: 57°C
GPU: 43°C
RAM: 43°C
Intake air: 38°C
Exhaust air: 34°C

This has been fun. I could have just cheese balled my way through this and used something like geek bench. I opted to use real world tasks instead as they are more important to me than benchmarking software magic numbers.

I did notice something interesting about CHUD and OS X nap mode. I belive that OS X, for my Quicksilver, enables nap mode by default. I can install CHUD, turn off nap mode and watch my temperatures climb. I can then turn it back on and watch them go back down. This is where it gets interesting. If I turn nap mode off using CHUD, then remove CHUD and reboot, my temperatures will go back down to nap mode levels. In the article Dan brought to my attention this is not the case. The MDD owner in the article can monitor his temperatures using software and watch them drop after enabling nap mode with CHUD. Based on my findings and the MDD owner's findings, I believe CHUD's benefits will vary model to model.

Given the period of time the Quicksilver came from, I do not believe these temperatures are bad. The highest temperature I got was 61C during a handbrake rip. I have seen plenty of PCs of similar vintage push out higher temperatures. However, I want the absolute best for my Power Mac. Despite these positive results, I still feel like I can make improvements to the cooling. I will continue to keep pushing onward.

The next phase will be experimenting with the fan orientation. Stay tuned and thank you for reading!

New ARM powered Freescale MCU sets modern example

While this is not a PowerPC chip; it is a RISC chip, and sets a perfect example for the modern predominant path of most RISC chips.  For those that don't know, an MCU (Micro-Controller Unit) is a type of SoC (System-on-Chip); which means it has the CPU, RAM and ROM on-chip to run embedded applications.  These are typically used in jets, cars, power generators and many other industrial based applications.

There are also PowerPC specific MCU development options like this that have been around for a while, and put all the capability directly in the users hands.  Much like Unix and Linux in the software realm; these SoC hardware and embedded development tools are only limited by the ability and imagination of the user.

This is why we should embrace the fact that we are no longer computing within the mainstream (and never really were); because even the current path of RISC steers far away from user friendly.

Solutions like these can literally turn engineering dreams into reality. 

Power Mac G4 cooling project: Phase 1 - The plan

I am excited to report that I am ready to kick off the Power Mac G4 cooling project. I have gathered all of the hardware I need in order to move forward. The goal is to incrementally upgrade the cooling fans and experiment with different intake/exhaust orientations all while monitoring the pertinent temperatures inside the case. All temperatures will be compared against the temperature of the original fans in their original locations. I will start simple by working with the existing fans and their mounting locations. Then I will move onto upgrading the existing fans while maintaining the same mounting locations. Ultimately the goal will be to add additional fans by changing the location of the hard drives and utilizing the liberated floor space of the case. Any case modification will have to absolutely look professional and clean. The ultimate goal is still in the brainstorming stages, the project will build up to that point. I want the project to be incremental so that it will benefit users of all comfort levels. I imagine that cutting up Power Mac cases may not be for everyone.

I have a hardware solution to monitor temperatures. I will be using a NZXT Sentry 2 to monitor the temperatures of 5 locations in my Power Mac G4 Quicksilver. The Sentry 2 was a pleasant surprise. It monitors two more locations than the other product I was looking at. The Sentry 2 also offers fan control in addition to temperature monitoring. The idea was to use this to temporarily monitor the temperatures during this project however I may wind up using it permanently some how. I was also able to buy it locally so I did not have to pay shipping.

I will be monitoring the...

Intake temperature

Exhaust temperature

RAM temperature

GPU temperature

CPU temperature

This will be a fun project. I look forward to sharing it with you all.