How to allow turbo mode on i5 540M?

Hello everyone,

I have a 2010 Acer Aspire 5742ZG (p614g32mnkk) with original BIOS v1.01 running on Windows10 for 2 years now (original was Windows7 Home) and I have recently done the following hardware upgrades:

from (original specs)...

• HDD 320GB
• 4GB DDR3 1066Mhz
• Intel P6100 (2.00GHz - no turbo)

to (all specs are brand new)...

• 2.5" SSD 240GB
• 8GB DDR3 1066Mhz
• i5 540M (2.53GHz - 3.07Mhz)

The problem is that after doing all of these upgrades and reinstalling windows, I tested the CPU with a game and I noticed it couldn't go further than the base speed of 2.53GHz... How to fix this and allow turbo?

 

TurboBoost does not work like you think - 3.07 GHz is only achievable if one core is under load. If both are you can't get past 2.53 GHz.
With i5 540M being a dual core CPU, these days you will end up having both core under load in every game therefore TurboBoost will not activate.

 

Oh... amazing.

Thank you for the explanation! But... in what situations would only 1 core be under load and the other not? I'm confused =P

 

Some applications still are single core/thread for compatibility reasons (OpenSSL being one of them) although admittedly that does not happen a lot these days. Vast majority of applications are multi-core, however remember that Core i5 540M launched at the beginning of 2010 and that might have made more sense then (I don't remember to be honest).

 

So... nowadays modern quad-cores, hexa-cores and octa-cores etc... with turbo, have their turbo appliable for all cores, right? Or just half of the existing cores?

 

So if I buy a Quad-Core or Octa-Core CPU, the turbo is will only work on a single core while the rest works at their base speed?

Sorry I got myself confused...

 

Maximum TurboBoost frequency that you see in specs always applies to a single core.

Here is how it words for a quad-core Core i7 7700HQ (chosen as an example because I own one )

Base frequency - 2,8 GHz
TutboBoost frequency for 3 and 4 cores under load - 3,4 GHz
TurboBoost frequency for 2 cores under load - 3,6 GHZ
TurboBoost frequency for 1 core under load - 3,8 GHz

That will differ somewhat for different CPUs but the principle holds true - max TurboBoost is for a single core under load, the more cores are under load the less the boost is.

EDIT: Also there is a TurboBoost frequency for both cores under load for your CPU but it'ss not exactly spectacular - 2,8 GHz up from 2,533 GHz base.

To answer your original question - you don't have to enable TurboBoost - it's there and works without the need for drivers. It's like SpeedStep - hard-coded into the CPU.

 

Thank you very much for your explanation!

I fully understand now.

So... considering that the game I was playing actually made the CPU reach the maximum peak of speed (according to base speed), and yet didn't activate the turbo boost dedicated of the Dual-Core, that means my motherboard might not support that turbo boost from Intel???

What do you think?

 

No, I don't think that's the case. TurboBoost is activated as long as CPU temperature is within a certain thermal envelope. If it's outside it TurboBoost won't be active. I did some testing on my Aspire 5740G and Core i5 430M in 2010 but I don't remember the exact temperature.
Sometimes TurboBoost was there for a while and then in time would fade away as temperature gradually rose.

If the CPU is supported by BIOS, TurboBoost is as well - there is nothing you can change or tweak about it.

 

I see, thank you!