This is a discussion on Did the CPU speed go up in 1.1.2? within the iPhone forums, part of the Apple iPhone category; I recently updated to 1.1.2 and have just now gotten around to reinstalling the SysInfo app. I had checked the ...
I recently updated to 1.1.2 and have just now gotten around to reinstalling the SysInfo app.
I had checked the Hardware specs within SysInfo before updating to 1.1.2 and the CPU Frequency was 400 MHz. The Bus Frequency was 100 MHz.
But now in 1.1.2 CPU Frequency is shown as 412 MHz with Bus at 103 MHz.
Can anyone in 1.1.1 test this? 1.0.2? 1.1.2?
I don't know if this is an update thing, a SysInfo thing, or perhaps the speed does indeed fluctuate.
Thanks,
Mike
"When this sign is under water, this road is impassable. -posted on a Tennessee highway
I'm at 1.1.2 and the same 412 cpu and 103 bus
400 CPU
100 bus
on 1.0.2
Most mobile ARM CPUs use some form of cpu scaling to make the most out of battery life - which is probably what you're seeing. I always thought the supposed Samsung ARM CPU in the iPhone was rated for 600mhz too.
If you think about it, it doesn't make sense to run the CPU at full speed unless there's sufficient load.
Using VT-Term100 or SSH you can run 'top' on your iPhone which gives you a live sys monitor (auto refresh). Using SSH you can leave this open and then run stuff on the iPhone. You rarely see CPU % go higher than 60% for more than a second. This leads to believe 400mhz is the battery saving frequency and it only runs at 600mhz when needed.
Good obvservation! I'd heard 600+ mhz as well, so this likely means that maybe Apple decided to trade off a bit in battery life to up the "standard operating performance level" of the Iphone. Or perhaps the new firmware introduced some other battery-saving measures, so they celebrated by giving us some more speed? Either way, it's pretty cool that they can do that with software alone, right?
Personally, I love the processing overhead on the Iphone... I think they really nailed it. It never really seems to slow down, even under full load.
I think the 600 MHz rumors were just that. I have found zero confirmation that the iPhone ever runs at that speed.
Moreover, I found this:
"Now let’s take a look at the CPU speed. Again, sysctl() is our friend, this time using CTL_HW with HW_CPU_FREQ and HW_BUS_FREQ. The results of our test show that the CPU is specified at 400 Mhz with a bus frequency of 100 Mhz.
There have been various hardware reports that place the ARM chip’s frequency above 600 Mhz. Maybe sysctl() is lying to us, or maybe the CPU is clocked down to give improved battery life. Only Apple knows that for sure."
http://furbo.org/2007/08/21/what-the...dont-tell-you/
So it seems the iPhone has indeed been sped up.
--
Mike
"When this sign is under water, this road is impassable. -posted on a Tennessee highway
~~~bumpola~~~~
OK, can anyone under 1.1.1 or 1.0.2 (or earlier) chime in?
So far it does indeed seem like the iPhone has been sped up in 1.1.2.
While I don't know if it's due to the "freshly updated" state that my iPhone has been in over the last few days, I am beginning to feel it running a little "snappier."
--
Mike
"When this sign is under water, this road is impassable. -posted on a Tennessee highway
Right, I'm not disputing that it's currently running at 400mhz or 412mhz in 1.1.2, but there's a good chance it is spec'd to run at 600mhz or so. The only way to test this is to run sysinfo and at the same time run something that puts 100% load on the CPU. If at 100% load it still runs at 400 or 412mhz then we have our answer.
As an example, set your laptop to maximum power savings mode and you'll notice it will run at the low clock speed most of the time, only jumping to max speed when it hits 80%+ sustained load. This is very common practice.
I also found a site that debunked the 600 MHz claim. Don't have it handy, but there are several out there.
For the record I can indeed stress the CPU (via multiple SSH sessions, all running tasks), but it never goes above 412 MHz (just as it never went past 400 MHz under 1.1.1). It also never drops below 412 MHz.
So, again, I am 90+% convinced Apple increased the clock speed in 1.1.2. It also doesn't seem like they are using CPU scaling in the iPhone at this time.
BTW: There is a lot of doubt the CPU is spec'd to 600 MHz. What I am saying is, even if 600 MHz is true (which I doubt) Apple capped to a lower speed to save battery life. This could be how they magically increased battery life a month before the device hit the streets. And, for some reason, they have increased it (a little) in 1.1.2.
--
Mike
Last edited by Tinman; 11-13-2007 at 03:06 PM.
"When this sign is under water, this road is impassable. -posted on a Tennessee highway