Why do all 4 Cores boost to 4.4 GHz when running Prime95

[cheapfrag2]

I'm running Prime 95 Small FTT test. I set the BIOS to enable turbo boost. The max multiplier for Core 0 and 1 are 44, then core 2 is 43 and Core 3 is 42. My Windows 8.1 power plan is set to balanced.

When I run Prime95, all 4 cores are reading 4.3895 GHz. Why is that. I thought under load, the CPUs wouldn't boost that high and I thought the 3rd and 4th core were restricted to 43 and 42 respectively.

Can someone explain why all 4 Cores are boosted to the max when Prime 95 runs?

 

[con635]

What cpu? If intel your board may have 'multi core enhancement' which will let all 4 turbo fully at same time.

 

[cheapfrag2]

Sorry, one minor correction. The BIOS was set to enable Turbo Boost but the max multipliers were set to Auto (there were numbers beside each setting which I mistook for the setting under the Auto option.) When I manually set the Core 0 and Core 1 to 44, Core 2 to 43 and Core 3 to 42, now when I run Prime 95, all four cores are reading 4.19 GHz so they are all restricted to the lowest multiplier when all 4 cores are loaded. That now makes sense to me.

I'm still surprised that it boosts at all under 100% load though.

My CPU is a i7-4790K and my motherboard is a Gigabyte GA-Z97X-Gaming 7

 

[DubbleClick]

The auto setting just thinks its safe to boost to 4.4ghz with all cores, which seems to be no problem considering you didn't mention instabilities.

Why bother when it's working fine? Free 0.2ghz increase 😉