"Turbo"

[jebem]

I recall the 80's when the IBM ISA PC was set as the standard for personal computing after a smart IBM move to publish the ISA architecture and BIOS in full in a very nice book (no eBooks in those times).
After that, the market was invaded with the so called PC clones coming from the Orient. I built one of these clones myself, by importing a motherboard PCB from HK.
Those PCB's had no components installed, so one would need to acquire and solder in all the required components (mostly TTL "LS" and "F" chips).
At last I used a EPROM programmer to literally clone the original IBM PC BIOS ROM, and voila, a new PC was born.
And yes, I had installed a nice "Turbo" push button to speed up the CPU and RAM!
I recall to have a few crashes when pushing the clock speed too much!
A few years later, nearly all the compatible IBM PC's had that "Turbo" option.

Those were the times before the term "Overclocking" took over the ancient "Turbo" expression.

I digress, I'm sorry if I'm upsetting our MoHPC fellows.

There is a good reason why the manufacturers uses a specific (under)clock speed on their products: Reliability

As I see it, when overclocking a system one needs to consider a few potential issues from using higher clock frequency (meaning more gate's switching operations per second):
1. Higher electrical current consumption depleting the battery's life in shorter time;
2. Higher working temperature as the current is almost converted into heat;
3. Shorter lifetime for the hardware: forcing the semiconductors to operate under high temperatures can cause degradation in gate leakage current or even catastrophic internal failures;
4. Running errors resulting from high temperatures while overclocking: digital circuits are complex in nature and one gate depends on the other, so when the transition times (0 to 1 or vice versa) are approaching the same values as the steady state times, the circuit starts to giving running errors;
5. The digital gates implementing the logic functions are very dependent on the clock speed: again, the mentioned transition times are the limiting factor to do overclocking and get away with it.

I know that the above issues are minimized when using modern LSI chips that runs MOS circuits consuming extremely low currents, allowing for higher clock speeds.
However I'm afraid there is no way to go around point (5).

That said, I'm for overclocking everything just for fun!
It is all about the human nature - to break our own limits!

Cheers