I recently upgraded my desktop to a sweet i7-3770. I noticed though through Intel’s turboboost monitoring utility that I was only getting 3.7Ghz turboboost speeds.
If we look on Intel’s website (http://www.intel.com/support/processors/corei7/sb/CS-032279.htm) about the turboboost speeds of our system, we find:
|Processor||i7-3770 – 3.40 – GHz|
|Max Intel® Turbo Boost Bin Upside||3||4||5||5|
|Max Intel® Turbo Boost Frequency||3.7||3.8||3.9||3.9|
So what that is saying is that at single or duel core load, the max speed is 3.9Ghz, at triple core load, the max should be 3.8Ghz, and at all full quad core load, the max speed is 3.7Ghz.
Odd thing for me is that I was never able to see the 3.9 or even the 3.8Ghz speed… I thought that perhaps Windows 8 always used all 4 cores, even some posts on the internet suggested that.
But I dug further and I found on wiki:
When the operating system instructed one of the active cores to enter C3 sleep state using the Advanced Configuration and Power Interface (ACPI), the other active core(s) dynamically accelerated to a higher frequency.
I realized that you need to make sure you have the ACPI C3 state option enabled in your BIOS. Some users who are looking to make their i7 perform the highest by disabling power saving features may actually be disabling the highest speeds for single core operations. I enabled this and now I get 3.9Ghz speeds:
Moral of the story – don’t disable ACPI to try to gain faster speeds, you might lose single/duel core turboboost!