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Intel’s new line of Core processors, based on the Nehalem architecture, will be taking over notebooks very soon. Several manufacturers, not Lenovo of course, have begun incorporating the Core i5 and Core i7 mobile processors into their notebooks and some will be available for purchase very soon.
The Core i7 models have a neat feature called Turbo Boost, which is nothing like the highly questionable Intel Turbo Boost that was Flash-on-a-mini-PCI-Express-stick intended to provide Windows Vista with some high performance cache.
Rather, Core i7 Turbo Boost dynamically alters the clock speed of each of the four processor cores below or above the default clock speed depending on workload and heat/power consumption. For example, if you are running a light workload that is spread amongst all four cores, a 2GHz Core i7 might overclock to 2.26GHz so long as the CPU stays within its heat specifications. Go the opposite tact and run a heavy workload that only utilizes one core, then the other three cores will power off and the active one will overclock up to 3.06GHz.
I don’t know about you, but I think that is a damn smart and exciting feature. It’s all about maximizing power efficiency, stopping power draw from un-used parts and getting the active circuits to a state where they can be idle and un-powered as well. While the chip may use a bit more power at the higher clock speeds, it can save far more power when sitting entirely idle & un-powered.
This is a very basic explanation, but what prompted me to post this was the excellent write-up over at The Register. I highly suggest you head over and check out their article if you like technical write-ups like this.
Source: [RegHardware]
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my i7 core is at 1.6 so lets say if i run a super heavy game, is it possible for the turbo boost to boost all four cores up?
Yes I’m wondering the samething too! And is there a way to keep it on all the time?
as I’m plugged into the wall most of the time
[...] Core i7-920XM. This beast comes with 8MB L3 cache, max single-core speed of 3.2GHz courtesy TurboBoost and only 55W max power draw [...]
The Core i7-720QM can use a maximum multiplier of 13, 13, 18 and 21 when 4, 3, 2 and 1 core are active.
In all Core i7 CPUs, the multiplier is completely dynamic and can be constantly changing. It can transition between the above 4 values hundreds of times a second based on load and how many cores are in the active state.
If you are running a single threaded activity and only a single core is in the active state, the multiplier can go as high as 21. If any background activity kicks in and wakes up a second core, the maximum multiplier will instantly drop to 18. If a third or fourth core becomes active then the maximum multiplier drops down to 13. As soon as the background tasks are completed, cores can go back to sleep which allows the maximum multiplier to increase. This is happening constantly.
Software like CPU-Z that samples the multiplier once per second might not give you a clear idea of what the constantly changing multiplier is up to. Intel recommends using the high performance timers within the CPU to accurately calculate the average multiplier over each 1 second interval. This method is outlined in the November 2008 Intel Turbo White Paper and is the method that both RealTemp and i7 Turbo use which can be downloaded from here.
http://www.fileden.com/files/2008/3/3/1794507/RealTempBeta.zip
i7 Turbo will clearly show you what each thread of your Core i7 CPU is up to.
Great description! I’ll share this as a new post
[...] unclewebb says: The Core i7-720QM can use a maximum multiplier of 13, 13, 18 and 21 when 4, 3, 2 and 1 core are active. [...]