Underclock vs overclock
- Thread starter jwerner15
- Start date
Underclock vs overclock
- Thread starter jwerner15
- Start date
gray_mouse
New Member
Let's say your processor clock is 2 GHz. If you overclock it will be over 2 GHz, if you underclock it will be under 2 GHz. Overclocking introduces instability, while underclocking introduces added stability,.
gray_mouse
New Member
iPhone and iPad are underclocked from factory to provide added battery life. Overclocking would decrease battery life, overclocking too much would also make it unstable. Follow a guide and do as others do. If you get problems, especially problems in temperature extremes like on the sun, go back.
Contrary to popular belief, Speed Intensifier is nothing to do with overclocking. It does nothing to the speed of your processor.
All this tweak does is change the animation timing of iOS. In a completely fake way it appears to speed up the device. The amazing thing is that this effect really does make the whole phone feel faster in use, but it has nothing at all to do with true overlcocking (i.e. forcing the processor to run faster than it was designed to run), which AFAIK is not possible on iPhone.
Another similar tweak is FakeClockUp, which essentially does the same thing, just with different options.
Ahhh well, you are right i think. But so far as the cpu can not be overclock, what elese can we do than enjoy those fake over clock tweaks for iPhone they give us in cydia? So that in the land of the blinds only the one eyed are kings
Let speed intensifier be it
What a horribly overgeneralized statement.
I have run various different CPUs overclocked with no loss of stability whatsoever. And certain CPUs can lose stability when underclocked, especially if the voltage dynamically adjusts itself downward.
jwerner15, the way it works is as follows: a CPU family is generally specced to run at a given range of clock speeds, for example most ARM Cortex A8-based CPUs run somewhere between 600MHz and 1.2GHz. A certain model within this family will be specced to run at a given clock speed within this range (for example, the rated clock speed of the Apple A4 chip is 1.0GHz).
If the CPU is run below this rated clock speed, it is considered to be underclocked. For example, the A4 chip in the iPhone 4 is underclocked in order to save battery life. If the CPU is run above the rated clock speed, it is considered to be overclocked; for example the TI OMAP 3430 in my Motorola Droid is rated to run at 600MHz, however; I always run mine at 1.2GHz. In this case, my CPU is overclocked 100% above its rated speed.
In the days when chip yields per silicon wafer were not very good, the clock speed of a CPU would be determined by testing the CPU at various clock speeds until it became unstable. The chip would then be rated based on this testing. For example, if an old school Intel Pentium MMX was stable at 150MHz; but became unstable at 166MHz, it would be designated as a Pentium MMX 150MHz. Nowadays, chip yields are much better, and it is more common for a CPU to be designated to run at a specific clock speed based on demand. For example, my Droid's TI OMAP 3430 was likely designated as such due to the fact that they needed OMAP 3430's (600MHz CPU core); it could probably have been rated much higher if for example the demand during that production run was for a faster CPU model. In these cases, the CPU would only be tested for stability up to the desired clock speed, and not beyond that (after all, testing takes time).
gray_mouse
New Member
A CPU let's say Intel Core2 Duo clocked at 2.0 GHz and the same one clocked at 2.4 GHz, they are identical, except the one at 2.4 GHz passed a certain criteria by Intel which allows it to be run at 2.4 GHz. If you overclock the 2.0 GHz to run faster you will most certainly loose some stability. It might run fine and all could be dandy during normal conditions, but have no doubt operating extremes will be scewed, and longevity of silicone will dramatically decrease. Why? Because from factory processor wasn't made to be run at higher clock speeds.
There are ways of overclocking iphone CPU, but it's just not practical. It all comes down to battery life. Iphone comes underclocked from factory for this reason.
There are ways of overclocking iphone CPU, but it's just not practical. It all comes down to battery life. Iphone comes underclocked from factory for this reason.
Some of us in the overclocking community use a series of tests that put the CPU and memory under extreme stress to prove stability, and run these tests for several days. The fact is, CPUs used to be binned according to capability, nowadays they are binned due to demand. For instance, most low-end Core2 processors can run significantly faster than their rated speed, and do so with complete stability.
If your overclock is unstable, you have gone too far. Plain and simple.
What CAN happen, however, is that the processor can break down quicker than it would at stock speed due to accelerated electromigration. But assuming you don't go crazy, we're talking a difference of say 8 years vs. 10 years of useful life.
I'm not saying overclocking is 100% safe, however if one is careful, it can be done safely and without undue risk.
