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View Full Version : How does my I7 work actually?



kimiraikkonen
08-10-2012, 09:06 AM
Hi guys,
I know the most of part about Core I series but i stumpled upon lots of different clock reports related to my 740QM in my G53JW. I want to learn that: Does my I7 downclock below 1.73 which is base-clock for 740QM. I think so because either Open Hardware Monitor, cpu-z implies it, but normally the I7 turbo-boost gadget stays 1.73 when the system is idle or under no load. The issue and another confusion related to clock speeds shown by cpu-z was posted here by me:

http://forum.notebookreview.com/asus-gaming-notebook-forum/582849-minimum-processor-state-corei7-confusion-win7-2.html (http://forum.notebookreview.com/asus-gaming-notebook-forum/582849-minimum-processor-state-corei7-confusion-win7-2.html)

Here is my screenshots, hope someone can interpret correcty:

10765

http://i54.tinypic.com/bi4c1s.png

The screenshots include Asus NB Probe, cpu-z and the Open Hardware Monitor with Turbo-boost gadget status when system is IDLE. Some cores' clocks drops to 980 mhz and some of them stays at 1700MHZ. When i throttle using TrueCrypt to put cpu into stress, 4 cores rises to 1.9 GHZ clock as expected.

Hope someone can clarify what's going on and how my I7 downclocks (Speedstep?) and overclocks (turbo-boost) on different situations.

Thanks a lot!

Gorman
08-10-2012, 12:46 PM
I don't know what you are confused about, it does exactly what you are experiencing.

Turboboost increases the CPU clocks speed in 133MHz increments up 2.93GHz.
Your CPU will scale down to whatever % you set it in your power management.

What exactly confuses you about that?

Zygomorphic
08-11-2012, 01:22 AM
Yes, I can...hardware engineer from Intel here :cool: ... not exactly :(

Yes, the CPU can - and does - clock down below 1.73 GHz when nothing is loading the CPU, this is known as SpeedStep, it has been around since the Pentium 3 days, which was a long time ago. However, the ability to speed up some or all of the cores of the chip dynamically based upon loading is called TurboBoost, as @gorman mentioned, and only appeared on the Nehalem (first gen i-Series).

The i3/i5/i7 make it look like there are twice as many cores because of Hyper-Threading, which is a method by which two threads can share different parts of the same core at the same time. Don't ask me how Intel did this, but they did. These semi-bogus cores appear to Windows as more processors, but they are 10-50% increase over just the physical core without HT based upon Microsoft testing.

Back to the TurboBoost technology. If the processor is running under its power and thermal envelopes, then it will increase the clock-speed of the cores if necessary to speed up the task. If not all the cores are being loaded, the CPU can down-clock them to the minimum speed via SpeedStep, and physically turn them off. This saves power and especially heat generation, which can allow the remaining cores to run even faster.

When Intel guarantees a speed, they are guaranteeing that all cores can run at that speed if the system load requires it, provided that the computer vendor cools the chip adequetely, which Apple, for instance, does not. Hardware Monitor is not reading the physical power status of the chip, only its clock frequency and multiplier, which is stored in memory.

kimiraikkonen
08-15-2012, 04:24 PM
Thanks for the explanations. I just wondered whether OpenHardware Monitor and CPU-Z are showing correct real-time clock speeds. My CPU minimum power state is set to %65 when plugged in so it's showing about 984 MHZ when quite idle. That means my 1.73GHZ 740QM can clock down till the threshold i set in minimum cpu power setting in power options under Windows 7?

I heard CPU will run at 1.73 even it's idle which seems a lie. EIST (Speedstep) is used to clock down to save power and extend CPU life as seen. And my CPU is throttled up when it needs to process more and more, and if it's a single-threaded application, it's Turbo Boost's turn!

Can somebody confirm everything is OK and the statement above is true?

Thanks!

Zygomorphic
08-15-2012, 07:13 PM
True! You are correct! The minimum threshold in Win 7 power settings is pretty much true - to the extent of my knowledge. My 2 GHz 2630QM goes down to ~800 MHz and no lower.

kimiraikkonen
08-17-2012, 06:05 PM
Thanks Zygomorphic, being a programmer it was a deal a for me to understand new I7 which is a hardware :)

By the way, when i play 3d intensive gams, i get almost 65-70 Celcius for CPU and 80-82 celcius for GPU under load. Are they both OK for my G53JW? Note that my CPU is 740QM (Nehalem). And not that i still couldn't find a good desk to place my G53JW, thus i'm using it on my flat (flat and hard) bed.

Thanks!

Yuxi3200
08-17-2012, 10:53 PM
By the way, when i play 3d intensive gams, i get almost 65-70 Celcius for CPU and 80-82 celcius for GPU under load. Are they both OK for my G53JW? Note that my CPU is 740QM (Nehalem).
Thanks!

Those temperatures are fine. Current Intel CPUs don't start throttling until 100C, and in my experience GPUs have similar or higher limits.

Zygomorphic
08-18-2012, 12:08 AM
Generally true, lower temps are always better though! Glad to help, I program some myself - for fun mostly! :) - so I try to keep abreast of the hardware developments.

kimiraikkonen
04-03-2018, 09:38 AM
Generally true, lower temps are always better though! Glad to help, I program some myself - for fun mostly! :) - so I try to keep abreast of the hardware developments.

Hi mate, after 6 years later. I want to update onw thing :)

My old i7 740qm in my Asus notebook always downclocks to 0.9 ghz, apparently 994 mhz (142 mhz bclk x 7?) WHEN IDLE*EVENTHOUGH MINIMUM PROCESSOR STATE is set to 100. But it throttles up to higher speeds when it's under stress with no problem, including turbo speeds.

Is that normal? Isn't Cpu relying on the setting on Windows Minimum Processor State and always downclocking to base speed when Cpu is completely idle, eventhough Minimum Processor State is 100?