I'm pretty sure the load of an interpreter interpreting "while true" doesn't challenge a CPU (agreed, it's not a JZ, but still). Percent load in an OS is nothing more that the inverse of cycles remaining free and with an application demanding unlimited slices it's 0%. It's not loaded.

I disagree with the fact that the same load provides an accurate benchmark. For example, at 250 MHz, while true gets 100 cycles, at 500 MHz you get 200 cycles (maybe), which is great to determine frequency. Cool.

However, should I overvolt the little bugger, you still get 200 cycles. Nothing is determined this way save for frequency.

When a real load is applied, things start to happen. Voltage drops (and is droop corrected on most machines), heat is being generated, components lose conductivity, resistance increases, and more power is needed. As a result, you get a different response curve for a script versus the heavy stuff.

As I said, I have an amp meter hooked up to my work CPU. The difference in load between a script loop, a heavy executable (Photoshop) and Linpack is visible on a 3 cm needle when switching frequency. Granted, this is a powerful and complex machine, more than the ARM we have in N900.

But I'm getting WAY off-topic even from my initial post. I'll wrap it up.

It is my opinion as a rather old overclocker that:

a) Nokia set the said limit most likely to keep the CPU from heating up and/or eating an inordinate amount of power. This has been carefully considered.

b) While it's probably overclockable to a decent degree with little risk during normal usage, hard conditions pose a risk to the CPU.

c) Heat protection is great to have, but is not the end of the story. By the time thermal shutdown kicks in, components are stressed by heat as they increase in temperature locally. This may or may not be enough to cause damage through repeated roasting.

d) Executing a "while true" in an interpreter at room temperature gets you no meaningful result if you ever forget the N900 on a car dashboard, running a graphics demo over wifi.

Take these, as always, with whatever size of salt grain you deem necessary. It was never my intention to hijack a thread on TMO and turn it into an overclocking thread. Sorry about that :)