Dell 1747 720QM turbo issue

Hi I've got a Dell 1747 with 720QM

but I got CPU-Z to check and even if I run the most CPU intensive programs (games, stress test programs etc.), it seems capped at around 2.2Ghz (Multiplier 15x or 16x).

It thought it suppose to go up to 2.8Ghz at Multiplier 20x?

 

This is kind of opposite to my situation. I am worried because my cpu does not fall below 20 multi. It usually stays at 21. I have high performance setting enabled and my temps are a bit high(stock cooling).

 

The maximum turbo multiplier is 21 for a Core i7-720QM but that is only achieved when a single core is active while the other 3 cores must be asleep in the C3/C6 state. Most Windows 7 laptops have 600 to 1000 background threads running when the CPU is idle. These threads are being scheduled on all 4 cores which constantly wakes them up. Every time a core wakes up to process a task, the maximum turbo multiplier immediately decreases so you will never average the full 21 multiplier for any 1 second sampling period.

Try running ThrottleStop. It will show you exactly what each thread is up to. If you run a single thread of a testing program like wPrime, and you use the Task Manager Set Affinity... function to lock wPrime to a single core, you should see the multiplier on that core max out while the other 3 cores spend the majority of their time asleep.

An average multiplier of about 15 while gaming is typical. Run ThrottleStop with the Log File option checked while gaming and you will be able to go back and see exactly how hard your CPU was working. Multi-threaded games were supposed to be a good thing but on these mobile CPUs, that just wakes more cores up more often and reduces your average multiplier so your CPU runs slower.

If you have a Core i7-720QM then you need to start using some software that correctly reports your multiplier. CPU-Z can be a little misleading at idle.

 

uncle, can I trust my resources monitor? It reports my freq. at 95-100% all the time. My temps run cooler when I use balance mode(cpu minimum @ 5%) and A LOT hotter when I use high performance mode(cpu min. 100%).

 

There is a lot of software out there that has decided not to follow the method that Intel recommends to determine the CPU multiplier and total MHz. I'm not sure why. Intel published this information in their November 2008 Turbo White Paper when the first Core i CPU was released. This information is no secret and is freely available. I know ThrottleStop follows that method so at idle you can compare what ThrottleStop is telling you to what other software is telling you. When you set the minimum processor state to 100% in a Core i mobile CPU, the multiplier will jump up and down continuously at idle. Each core bounces back and forth between the maximum of 21 and the minimum of 7 averaging somewhere in between. The multiplier is not a steady value like some software tries to tell you it is. It can be constantly changing when two different power settings are both trying to control the CPU at the same time.

In theory, going by your core temperature should be a reliable method but sometimes different settings also affects fan speeds and cooling so core temperature might not always be an accurate indicator that you can use to make comparisons.

Dropping the Minimum processor state down to 5% should help your CPU drop its multiplier and MHz to its minimum when the CPU is idle. On the 45nm Core 2 mobile chips, this looks nice but doesn't make any difference to idle power consumption or core temperature. Those CPUs go into the low power C3/C4/C6 state automatically regardless of any user settings. I haven't tested a Core i7-720QM yet. Windows Performance Monitor has the ability to measure battery power consumption. This makes it's easy to compare different setups while on battery power to see the differences in power consumption. That's cheaper than buying a Kill-a-Watt meter and is also more accurate.