Does the iphone cpu frequency change when the cpu load is different?

CPUs in every computer (yes, it is one) operate at a fixed frequency.

tonefox wrote:

CPUs in every computer (yes, it is one) operate at a fixed frequency.

Not necessarily true. The new Ivy Bridge Macs have a dynamic

"Turbo Mode" that bumps clock speeds under high demand.

Many Sandy Bridge based PC's also have a turbo mode although

it seems Apple disabled this feature on Macs.

Many Android phones use dynamic clocking

to conserve battery.

The A5 processor in the iPhone has dynamic

clocking capability. It is unknown whether it is used since the

APIs and app limitations prevent anyone from finding it out.

As a general, historical statement Tonefox is correct. For certain particular cpus woodmeister is correct. Cpus have historically been single frequency units, though over-clocking has been done for several years. Doing so pushes the cpu beyond its guaranteed speed, but has tended to work since most cpus from quality vendors will actually operate at higher speeds. The manufacturer just does not guarantee the results...remember the Pentium fiasco in the early years of that chip? Today manufacturers are ceertifying particular product lines for over-clocking on a periodic basis. And that is what dynamic clocking really is, over-clocking but not at a constant clock speed as has been done in the past.

Much of the silicon on the market will function at higher clock rates, the only question is does the maker guarantee the accuracy and performance at those clock rates.

Ralph Landry1 wrote:

As a general, historical statement Tonefox is correct.

I would have to admit to being, in general, quite historical. My first clock speed was 1Mhz.... 🙂

Thanks for the comeback, the both of you. If I may wriggle - I still say the CPU operates at a constant frequency: what you are saying is that that frequency may be switched to a different one at times. Yes?

Yes, whether it is given a fancy name like dynamic, turbo boost, or whatever, it is all temporary over-clocking.

My first computer was the Sinclair, followed by the Apple IIe (which I still have and still runs) so 1 MHz looks very fast 😁

tonefox wrote:

Thanks for the comeback, the both of you. If I may wriggle - I still say the CPU operates at a constant frequency: what you are saying is that that frequency may be switched to a different one at times. Yes?

Yes, f demand requires a boost, the frequency will bump

up (as in the new Macbook Pros). And in other situations

if demand is minimal, the clock can be bumped down.

Many microprocessors these days now have the capability

via software to dynamically control clock frequencies through

software, not just sleep or run. This has been pretty much been

pushed by the increasing demand of portability and battery powering.

Ralph Landry1 wrote:

Yes, whether it is given a fancy name like dynamic, turbo boost, or whatever, it is all temporary over-clocking.

Or under clocking for lack of a better term.

My first computer was also a SInclair. The next was the TI-99 w/expasion box

and a whole 32k of RAM.

woodmeister50 wrote:

My first computer was also a SInclair.

Nope. 😉

http://en.wikipedia.org/wiki/MK14

Must be one of them young punk kids 😁

The Sinclair ZX-8 was the first I "owned".

The first computer I could get access to via terminal

with some real operating system was a PDP-10.

Before that the only access to a computer was through punch cards

and a keypunch machine.

Sounds about right, started on an IBM 1620 then to the 360 and 370, finally to terminal in an adjacent room. Eventually to the Sinclair, and Apple and IBM and Mac and DEC and Sun platforms.

After using these things since 1964...hard to remember all the excitement of the earliest days.

Just ahead of me: the ICL 1900 series, 1968.

What was ICL, a British take off on IBM??? Remeber the Space Odessy movie and HAL, IBM minus one letter?

International Computers Ltd! The British computer industry! Eventually became an arm of Fujitsu.... they failed after I left....