Investigation continued
Why is Intel Turbo Boost Not Working On My Laptop? (Continued)

Dell Latitude E6420 is my laptop with Windows 7 Enterprise. Turbo Boost is enabled in BIOS but is disabled in OS according to AIDA64. I managed to install Intel Turbo Boost Monitor but it says that Turbo Boost is not enabled. Although I still see standard speed but I also see "Energy Saver" appears when CPU runs at less than standard speed.

What is interesting is that Turbo Boost gets enabled in OS only when SpeedStep is enabled as well in BIOS. This slows down CPU to ~700Mhz and stays there no matter what. Enabling\Disabling C-State did not do anything and there is no multiplier.

Intel Chipset Utility is the latest version and I did not find any Turbo Boost driver, nor any service in Administration.

I have found drivers package for my model here. The problem is that i do not know what is responsible for Turbo Boost.


Latest generation Intel processors automatically under clocks your processor in order to save energy when you are not using it. Seeing "Energy Saver" listed under the monitor program is nothing to worry about.

From Intel:

Turbo Boost -

Intel Turbo Boost Technology 2.0 is activated when the Operating System (OS) requests the highest processor performance state (P0).

The maximum frequency of Intel Turbo Boost Technology 2.0 is dependent on the number of active cores. The amount of time the processor spends in the Intel Turbo Boost Technology 2.0 state depends on the workload and operating environment.

Speed Step -

Enhanced Intel SpeedStep® Technology

Enhanced Intel SpeedStep® Technology is an advanced means of enabling very high performance while also meeting the power-conservation needs of mobile systems. Conventional Intel SpeedStep Technology switches both voltage and frequency in tandem between high and low levels in response to processor load

From what I can tell and have seen, these two technologies are highly linked. Turbo Boost is a feature that has come from Speed Step (that has been available for a long time) and enabling Turbo Boost requires Speed Step to be active.

I would say that your BIOS is lying to you and it should disable the ability for Turbo Boost to be changed whilst Speed Step is disabled. From looking at some of the laptops I have on my bench, Speed Step can not even be disabled - it is a good feature that can increase the battery life quite a bit and I am not sure why you would want it disabled.

Also, if you really want to update, go to the official Dell site, type in your asset code and download the latest BIOS/EFI Updates and chipset drivers. I think the BIOS/EFI has the best chance here but, it never hurts to update the chipset drivers either.

  • I'm not sure if "idle states" are the same as SpeedStep, but you can disable them -- you can unlock the appropriate options in the Power Options dialog and then set them to Off. (Your CPU will no longer idle, so your computer will obviously heat up and it's not good for your CPU.) – Mehrdad Aug 17 '11 at 15:36
  • And how to do that? – Boris_yo Aug 19 '11 at 9:33
  1. Make sure you've got all devices installed in Device Manager
  2. Make sure you're updating your Dell from Dell's website (which also uses your Service Tag to be able to find the right drivers for your model). Most of the devices in driver pack you linked in your questions are older then the ones you get by directly downloading and installing your updates.
  3. Try updating your BIOS. There were lots of fixes in A05 version for E6420 (which I do have as well with I7 processor and it seems to work just fine. )
  1. Added support for Signed Firmware Updates.
  2. Additional vPro support. Added DASH ‘PLDM for BIOS Control and Configuration?
  3. Updated the Password Bypass feature.
  4. Fixed issue where the system would not reboot the first time after disabling the Integrated NIC in Setup.
  5. Addressed issues with the 'Auto-On Time' Setup field.
  6. Fixed issue where a UEFI OS install would fail with greater than 8GB of memory.
  7. Addressed intermittent boot issues in ATA mode.
  8. Fixed issue in ATA mode where unaligned memory accesses would fail.
  9. Fixed issue where the BIOS would reboot instead of flashing when the /S parameter was used with the flash executable.
  10. Fixed issue where the error log data from the previous POST would show up if you shut down the machine at the F1/F2 prompt.
  11. Fixed issue where the IDT audio device would not appear in device manager when running a UEFI OS.
  12. Updated to the MOB_P_08 version of the Intel microcode patch.
  13. Updated to the 1.3.72 version of the Intel PXE OROM.
  14. Updated to the 4208 version of ePSA diagnostics

EDIT: Consider updating to newest BIOS A08

Changes are:

1. Fixed issue where Intel Turbo boost non-functional. (sound familiar?)
2. Fixed issue where TDM PBA SSO doesn't work when both FP and TDM PBA SSO are set for single user. 
3. Addressed some keyboard with USB Hub not accessible during POST.
4. Updated to the 1.4.0 version of Intel PPM Reference Code. 
5. Updated to the MOB_P_13 version of the Intel microcode patch. 
6. Intel Trusted Execution Technology updates 
7. Updated to the 1.05 version of Dell GPE. 
8. Added new key for Signed Firmware Updates. 

Note: 1. Please note that if the A04 or before A04 BIOS is currently installed on your system, you must first update to A05 BIOS and then flash to the latest A-rev BIOS.
  • How BIOS A05 is working for you so far? – Boris_yo Aug 19 '11 at 9:31
  • 1
    Yes and it has 1. Fixed issue where Intel Turbo boost non-functional. (sound familiar?) in it's change log so go and upgrade .. in my answer you've got full change log. I haven't seen bios failure for my lifetime. Of course make sure you've got enough power. – MadBoy Feb 1 '12 at 19:56
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    Ye, like connect your laptop to power outlet and have battery full or so. That should be sufficient. Unexpected power failure can cause what you are afraid to .. a bios crash ;) – MadBoy Feb 1 '12 at 23:01
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    If it's badly prepared BIOS or some crash happens in the middle then sure. Right now most companies use check-sums for BIOS so they check before applying if BIOS is good. But like I said. I haven't had a problem with wrong bios in my life time. Of course you can be the one with bad karma... – MadBoy Feb 2 '12 at 8:12
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    It will be done by program itself. Just run it and that's it. – MadBoy Feb 2 '12 at 23:17

Try plugging in your computer. My turbo boost only works when my computer is charging. I think that the default settings disable it when its not charging. It saves power. Turbo boosting is so nice for games though, try to always play while charging!


In Windows 8 the CPU monitor would always show the same speed and so would the Intel Turbo Boost monitor, even when I was pushing the CPU.

I went to power options (laptop), and went from power saving to high performance and now the Turbo Boost comes on when I need it.


Turbo boost will only work under certain curcomstances.

The first thing that comes to my mind why it "won't work" (note quotation marks) on your laptop is becuase working temperature of your CPU is already high enough and CPU, of course, won't go into destructive mode by overheating himself. Another thing it might be that your CPU is already at peak TDP (Thermal Design Power) and it won't fire Turbo Boost.

Also you might be at your maximum power consumation. I'm assuming that Turbo Boost is enabled in BIOS. According to Intel (and my personal experience) - to get it work only thing you have to do is to enable it in your BIOS.

Anyway, and I can stress this enough.

DON'T OVERCLOCK YOUR LAPTOP(S) (Turbo boost = overclocking)

Not only it your battery life is shorter, but overall temperature of your system is higher and life of your laptop is shorter. If anything, you should look how to undercloack CPU. It's not desktop computer, it already has hard time with heat dispersion.

  • 1
    Turbo Boost is SMART overclocking so it is safe compared to standard overclocking. – Boris_yo Aug 15 '11 at 10:00
  • Indeed, that's why it might be a reason why your CPU speed is not higher when Turbo Boost is on. – StupidOne Aug 15 '11 at 10:13
  • I think you're wrong on this one. If the Mhz is at 700 as the OP says it's most likely lowest possible value. I have exactly same laptop and it does jump from 700Mhz to 3000Mhz when I start doing something. Even when I start typing it goes up to 3000Mhz from 783. Also saying he shouldn't overclock his laptop is completly wrong in this case. It's standard Intel feature. If you're not doing anything then your laptop stays at 700Mhz, if you do something it jumps to higher speeds. It does behave differently on Battery and normal Power. – MadBoy Aug 18 '11 at 17:55
  • I still don't see what's the connection between your laptop and his problem. It's not just about having the same CPU. You have to met other condition as well (temperature, power, load, etc.). Yeah, it is Intel's feature (AMD's version is called Turbo Core, it's pretty standard feature in todays CPUs), but it is still basicly OC and if requirements are not met, it won't fire. It's not - "Click the button and it will work" kind of feature. Also, I don't believe simple text editing will force TB to OC CPU to 3GHz. Cold-booting text editor might, on the other hand. – StupidOne Aug 18 '11 at 19:57
  • When simple text editing occurs, then Turbo Boost may kick in but only for a couple of seconds. I did not see it constantly stays at high MHz. – Boris_yo Aug 19 '11 at 9:33

guys just upgrade your power supply to more higher Amp if your are using 65 Watt power supply the bios will tell the OS that your power supply is not capable of delivering the power it need on your cpu and gpu that's why your getting throttle down frequency, because i try using 65 watt power supply then when i start the dell latitude e6420 the bios detected it and warn me and after that i had notice the cpu frequency had been down clock around 800 MHz, then i use 90 watt power supply and it run normally also turn on the turbo boost up to 3.2 to 3.3 GHz but I also notice 90 watt is kind of a bit hot then i try 130 watt power supply then that do the trick the Laptop just work fine at heavy load plus the power supply do not get to much hot even the laptop is on heavy load process or some gaming or doing some stress test. Kinda a bit common sense i7 cpu uses high AMP to work well just give you device good ample of room on power supply even the Manufacturer say this device uses 19.8 V dc and 3.5 amp it is not good if your power supply have that same capacity, yes in short run it will work but your power supply will work crap ton hard just to give that power that is your device needed.

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