On Pentium Up using only 5A power, what is maxium cpufreq?
Hello, so when I originally purchased my Up Gateway box, I completely forgot to also purchase a PSU with it... Locally I could only find a PSU at 5V 5A, however the recommended Amps is 6A, while most people say it does work with 5A as long as you do not connect too many devices to Up board. Since this is only going to be an Internet gateway/firewall device, it won't require many devices besides two Ethernet cables. It has been working perfectly with 5A, until today when I decided to install VirtualBox, and it rebooted itself once I began compiling the kernel module required for it. Compiling always drives up the CPUs to their max due to their nature... After figuring out the low amperage was the issue during the compile, I decided to look into cpufreq to see if I can keep the CPU's max frequency low enough so that it can still function perfectly with only 5A. Here is what I did with cpufreq, and tested that it indeed does not go higher than the max I provided:
[email protected]:~# cpufreq-set -c 0 -d 800Mhz -u 1.7Ghz
[email protected]:~# cpufreq-set -c 1 -d 800Mhz -u 1.7Ghz
[email protected]:~# cpufreq-set -c 2 -d 800Mhz -u 1.7Ghz
[email protected]:~# cpufreq-set -c 3 -d 800Mhz -u 1.7Ghz
Using "cpufreq-info" during the module compile process again showed that it remained stable, and the CPU did not go over 1.7Ghz. However, I am wondering if anyone else has tested this out, and figured out a sweet spot frequency to use here. I should note that even when not doing a compile, the CPU frequency of a single core was able to go up to 2.5GHz with no problems, issues seem to arise when all the cores are pinned at 2.5Ghz for too long. It can technically survive at 2.5Ghz for a few seconds without dying, although this is probably not good for the processor itself... I am wondering if something else might have been taking additional power during the compile when the cores were pinned at 2.5Ghz, as I only experienced this compile-based reboot of the unit just once. To be safe, I'll be keeping all the cores at 1.7Ghz until I can figure out a good sweet spot for 5A power.
So in case you did not want to read my entire store, the question is, does anyone know of the maximum core frequency for the Up Pentium board to run stable without using more than 5A with only 2 Ethernet cables being used. No display or USB devices are plugged in. Cooling is done passively using a mega head sink provided by the Up Gateway system kit.