How to know if CPU is running at full speed ?

[RobPhoboS]

Hey guys,

I'm a 3D artist, and I'm currently rendering out a whole load of frames. I'm using a reasonable, Sony Vaio laptop for the task, which has an Intel i7-720QM, however I'd like to know what CPU speed it's currently operating at.
I know that it says it runs at 1.6Ghz as standard but then can ramp up to 2.8Ghz, I just wondered if it truly was going at that speed whilst it's rendering.

 

[DeaconFrost]

The easiest way to tell is to run something like CPU-Z in the background while you are applying a load to the processor.

 

[Bill2]

You can also check in Resmon (maximum frequency under CPU tab).

 

[RobPhoboS]

Thanks guys.

Looking at CPU-Z, when it was idle the cpu core was at around 2.7Ghz, now it's rendering it has dropped to 1.7Ghz... (actually seeing it drop to 950Mhz...)
Eh, doesn't make sense it should have gone up, right ?
I'm using a Zalman large laptop cooler underneath it, seems to keep the temperatures reasonable for long periods of time.

I did just find this:
http://www.intel.com/cd/channel/res...cessors/pentium-d/tech/203838.htm#Integration

 

[Bill2]

Throttling?

 

[sygnus21]

Thanks guys.

Looking at CPU-Z, when it was idle the cpu core was at around 2.7Ghz, now it's rendering it has dropped to 1.7Ghz... (actually seeing it drop to 950Mhz...)
Eh, doesn't make sense it should have gone up, right ?
I'm using a Zalman large laptop cooler underneath it, seems to keep the temperatures reasonable for long periods of time.

I did just find this:
Enhanced Intel SpeedStep® Technology - How To Document

The standard clock speed of that processor is 1.6 GHz, when the processor overclocks itself (Turbo Mode) it’ll run as high as 2.8 according to the link you provided (Intel i7-720QM).

In short the standard everyday clock speed of the processor is 1.6 gig, the turbo mode can push it as high as 2.8. If the task at hand doesn’t need that much of a clock boost, then the CPU isn’t going to use turbo mode. So…. If the rendering you’re doing doesn’t push the CPU that hard, it’s not going to ramp up that high.

What is Intel® Turbo Boost Technology and how does it work?
Intel Turbo Boost Technology is a way to automatically run the processor core faster than the marked frequency if the part is operating under power, temperature, and current specifications limits of the Thermal Design Power (TDP). This results in increased performance of both single and multi-threaded applications.

For more information see the Intel® Turbo Boost Technology 2.0 page.

Processors — Intel® Turbo Boost Technology frequently asked questions

 

[logicearth]

Are you sure the rendering task is CPU bound? Could be GPU bound?
Can use Processor Explorer which now has GPU metrics.

 

[RobPhoboS]

Hi,

It's 100% cpu rendering I'm doing, I'm going to check out the bios (if it lets me) to see if anything is amiss in there.
Trust me, this is possibly one of the only things that would use 100% of the CPU, as that is how the images are calculated.
Very odd why it's dropping speed.

The only option in my laptop's bios was the intel virtualization option.


Laptop = Sony Vaio VPCF11Z1E

 

[solarmystic]

Actually it sorta makes sense that your CPU speed is dropping..

The Intel i7-720QM is a quad core processor that turbo boosts to a maximum of 2.6 GHz according to the number of cores that are being utilized.. Say your app only uses one core.. the processor will switch off 3 cores and turbo 1 core to 2.8 GHz... it sounds like your rendering program uses all 4 cores; consequently, the speed drops to the rated nominal 1.6 GHz for 4 cores... This is done by design i think....

tldr; the more cores the program uses, the lower the speed will be... Reference : Intel® Core

EDIT: Beaten to the punch =P

 

[RobPhoboS]

Ahhh - ok now that makes sense.
When it's rendering it has 8 'buckets' on the go, thus dividing the chip up quite a bit.

I just thought it was odd when I first saw the numbers coming up.