4790K odd turbo behaviour

[DDebbil]

Just been trying out a 4790K on a couple of different motherboards, but found that they seem to treat the turbo differently. On Prime95 with my Z87 based Gigabyte board, the CPU is running 4.2GHz all cores, which I gather is the maximum all core turbo. But on Prime with my Z97 based Gigabyte board, the CPU is running 4.4GHz all cores. Could this be a case of 'stock setting overclocking'? I've heard of that, but a bit surprised to find it within the same company on two similar boards. Both boards have BIOS reset to defaults (other than XMP).

[Fasauceome]

you might find something labelled "all core enhancement" or something similar, a feature shipped with high tier boards as a sort of auto overclock.

[Chronified]

Stock Turbo for your CPU is 4.4Ghz

https://ark.intel.com/content/www/us/en/ark/products/80807/intel-core-i7-4790k-processor-8m-cache-up-to-4-40-ghz.html

 

the Z97 Gigabyte board likely has "all core turbo" "all core enhancement" "all core boost" or a similar setting enabled by default. I wouldn't complain tbh. 

[Chronified]

Also, pls pls don't use XMP profiles.

 

"Friends don't let friends use XMP" -Linus Sebastian 

[DDebbil]

I thought the 4.4 was the max single core turbo and 4.2 was the max all core - is that not right?

[Fasauceome]

2 minutes ago, DDebbil said:

I thought the 4.4 was the max single core turbo and 4.2 was the max all core - is that not right?

That is true, and the all core enhancement feature makes all cores go to that frequency

[DDebbil]

The auto overclock seems to draw a lot more power and raises temps considerably compared with stock

[Livin]

2 minutes ago, DDebbil said:

The auto overclock seems to draw a lot more power and raises temps considerably compared with stock

It does which is precisely why some will turn it off.  You may be able to reduce the temperatures by undervolting a bit, but it can take a bit of time and patience tuning in a stable lower voltage while keeping the frequency bump.  There has definitely been controversy about this being on by default.  Just because you are buying a higher end motherboard doesn't necessarily mean you want to (or know how to) deal with the potential side effects.  The 4th gen i5/i7 unlocked CPUs still came with a boxed cooler, and there's no way I'd run one of those CPUs on the stock Intel heatsink with that setting turned on.