Intel turbo boost not working when 4 cpu cores are in use.

[Bob19199]

I have an i7-3630QM cpu in my laptop, which should turbo boost to 3.2 GHz (for 4 active cores), 3.3 GHz (for 2 active cores) and 3.4 GHz (for 1 active core).

However, after noticing bad performance in a game, I checked task manager and noticed my cpu is only going up to 2.4GHz, which is its base speed.

I then downloaded Intel Extreme Tuning Utility and did a benchmark, which confirmed this, and also let me see that when one core is in use, turbo boost is active and works as it should, but when 4 cores are in use, turbo boost doesn't seem to be working.

Does anyone have an idea as to why this is happening, or what I can do to fix it?

 

[Ecky]

Are you certain about those turbo bins? It's typical for desktop CPUs to turbo 4 cores up to 200mhz below single-core turbo, but this is a 45w notebook CPU.

A quick google search revealed someone else asking this same question about 3 years ago:

http://www.tomshardware.com/forum/id-1692720/intel-3630qm-turbo-boosting.html

 

[Solandri]

That's the correct turbo boost speeds for that CPU. 2.4 GHz + 8/8/9/10.

What CPU temps are you seeing? The advertised turbo boost speed is the max attainable. If the CPU is running hot, you may not reach those maximums, or it may not even turbo boost at all.

Also, check to make sure your laptop's power profile is on high power (assuming you haven't modified it). Usually manufacturers create a "balanced" power profile which runs by default and enables some power saving features. Your manufacturer may have turned off turbo boost in this mode.

Check your BIOS settings as well. Some of them let you turn off turbo boost (and hyperthreading) there. I mention hyperthreading because if your CPU is overheating, you may actually be able to improve performance by turning off hyperthreading. Only a few specific apps really benefit from hyperthreading. On most other apps, it just causes the CPU to run a lot hotter for little performance gain. If you're running into thermal throttling, having hyperthreading on could cause overall performance to decrease.