Windows 10: CPU Clock speed locked at 0.79GHz

Hi, I have an i7-4500U CPU and for the last few months my system starts at full speed (2.39GHz) but as soon as the CPU goes below 30% utilisation after startup, the system locks the clock speed to 0.79GHz even when the fan is off. The CPU temperature is around the 50degree C mark, therefore should be allowing the processor to go up to full clock speed.


I've changed the power settings to set the minimum clock speed to 50%, but that has made no difference.

:)

 

CPU Clock speed with Belle Update

I would be surprised if the rest of the hardware in the phone, like the RAM etc, couldn't support the maximum CPU clock speed. When such sophisticated electronic devices are designed it's impossible to know until it's all been put together how it will actually
perform as a complete unit - the hardware, software, battery capacity, etc. The clock speed allows a fine-tuning once everything comes together, to get the optimal balance.

Well-made software makes a huge difference to how much CPU/hardware resources are required. Software efficiency is the most important factor of all.

A GPU is only there to perform tasks that would otherwise take up huge amounts of CPU resources. Dedicated graphical tasks such as 2D scrolling, 3D texture-mapping/filling for example. But that's all. The CPU is still running the whole show, but just has much
of the load taken off it by the GPU.

So with the GPU doing more and more, the CPU and it's speed become less relevant.

 

CPU Clock speed with Belle Update

I'm no great hardware engineer, so can only relay what I've read and my interpretation of that information...



Apparently the N8 (in particular - not sure about other models) is designed from a hardware perspective around the graphics processor and it's capabilities. The idea is that all interaction with the phone is through the display, so there's a dedicated processor
to handle the interpretation and response to anything happening on the screen. The CPU in this design does very little other than actual execution of programs running on the phone. Because those two processors have to communicate in the most optimal fashion
possible, the CPU (although capable of faster speeds) is slowed down to match the graphics processor.



It may seem a silly design decision to slow the CPU down, but when you consider that the graphics processor takes much of the load from the CPU (apparently unlike in other phone designs), then you can understand that the N8 is faster than phones with much
faster CPU's.



The upshot of all this though, is that speeding up the CPU would almost certainly not make the N8 faster (may in fact make it slower as the CPU waits for the graphics processor in mismatched clock cycles). I guess we just have to be impressed by Nokia's
design to get so much more out of a phone with so much less...



Cameron



PS this would be an interesting discussion for one of Nokia's hardware engineers to step into and confirm one way or the other what the impact of changing the CPU speed would be on the N8.

 

CPU Clock speed with Belle Update

A few things here, some of what you have mentioned I agree with. But some I dont. Firstly when any device is designed, things like the GPU and RAM are all allowed for, that is the speed at which each is capable. There is no use taking pot luck saying oh
we think that will be enough. Its all calculated right from the word go.



Its done for several reasons, firstly costings, there is no use producing something that is so expensive no will be able to afford it. secondly to make sure you dont end up with bottle necks in data flow. Also it no use producing something that is so slow
that you cant do anything worthwhile on it. That is some of the reasons.



You are absolutely right about software, well made software installed in a relatively slow running device can quite often beat poorly designed software running on a fast machine at exactly the same task. O/S like windows for instance, in my opinion only,
whilst full of features, is definitely bloated, and not well designed. A standard install disc for windows these days is around the 3Gig mark (depending on version of OS), where as something that does exactly the same thing like Linux still fits on a 700M
cd.



And you are right about the GPU, its does relieve the pressure on the cpu. Unfortunately the gpu in an N8 or an E7 is only running at 200Mhz. Considering most things are graphical based on these phones. I would have to wonder how much of the gpu is being
used, especially when the one chip is running everything from the 2d/3d graphics/rendering, the camera up to 12MP, HDMI, HD video recording and play back, a stack of video codecs etc.



Unfortunately the main cpu from everything i was able to find is simply listed as an ARM11, these processors run on several Nokia's phone, including the older E90 (which had dual cpu's but ran at much slower speed of about 332 Mhz., however the Arm site
list the ARM 11 as several versions, including one that actually has 4 cpu on the one the chip but only presents itself as 1 cpu to the rest of the hardware, with this cpu running anywhere up to 1Ghz. So its entirely
possible that the 680Mhz listed for the N8/E7 could be as fast as it goes. Also the current versionof the ARM11 have a power consumption of 0.21mW/Mhz. so based on that figure a processor running at 680Mhz would consume 142.8 mW, but at 1G
it would be 210mW, that a difference of 67.2mW. That would mean your phone would go flat a lot quicker. This info is based solely on information that I can find on Nokia run sites, ARM's site and broadcoms site. That way we can beleive what we are able to
read with some certainty. I did find other non-related site suggesting 720mhz for the cpu, but they are only a 3rd party mobile news site, that said it had been suggested that it was capable of 720Mhz..



But i do firmly believe with efficient code the phones can perform extremely well, Anna certainly seems faster than the old Symbian ^3 version that was on the phone prior to Anna, whether or not Belle can be made any more efficient remains to be seen. But
heres hoping.