2015 5K iMac not Turbo Boosting?

[arbitrage]

With all the hoopla around the new MacBook Pro I became aware of the Intel Power Gadget and installed it on my late-2015 5K iMac with the 4.0Ghz i7 (i7-6700K) which is supposed to turbo boost to 4.2GHz.

The IPG never shows it go above 4.0GHz no matter what I throw at it. It just pegs at 4GHz. Is something wrong or is this normal for that processor and I'm not understanding how it should work.

On my 2012 15" rMBP it shows it Turbo Boosting up from 2.7Ghz to about 3.5GHz as it is supposed to (I think it is rated to 3.7 GHz but I'm just doing LR brushes, not video to test it).

What is up with my iMac?

 

[Thanos812007]

Btw you don’t have any throttling? Mine goes to 3.6 -3.7 when I use for example handbrake..

 

[arbitrage]

Btw you don’t have any throttling? Mine goes to 3.6 -3.7 when I use for example handbrake..

When I ran Cinebench it throttled down as low as 3.8GHz but I haven't tried anything more sustained than that.

 

[cwanja]

If I take the .2 GHz you are not worried about on the MBP turbo boosting, why are you worried about them on the iMac?

 

[arbitrage]

If I take the .2 GHz you are not worried about on the MBP turbo boosting, why are you worried about them on the iMac?

I just was wondering why it never does any turbo boost at all. Not really worried about 0.2GHz

 

[ondert]

Does it have to boost up to 4.2ghz on all cores?

 

[MandiMac]

With all the hoopla around the new MacBook Pro I became aware of the Intel Power Gadget and installed it on my late-2015 5K iMac with the 4.0Ghz i7 (i7-6700K) which is supposed to turbo boost to 4.2GHz.

The IPG never shows it go above 4.0GHz no matter what I throw at it. It just pegs at 4GHz. Is something wrong or is this normal for that processor and I'm not understanding how it should work.

On my 2012 15" rMBP it shows it Turbo Boosting up from 2.7Ghz to about 3.5GHz as it is supposed to (I think it is rated to 3.7 GHz but I'm just doing LR brushes, not video to test it).

What is up with my iMac?

I think 4.2 GHz only count if the task you‘re doing is purely single-threaded, means it‘s using only one core.