A silly question about CPU.

[thedragon0000]

My friend, she has a PC with i7 4790S 3.2GHz-4.0GHz (turbo boost). But when she was rendering her video I notice that CPU was at 99% but the clock speed was only at 3.55GHz max and it never went higher than that. Can you guys explain this for me please, i thought 4.0GHz is the maximum clock speed when running some heavy work load.

[msvelev]

The 4.0GHz boost will kick in only when max 2 cores are working. When all 4 cores at at 100% there will be a lower boost (seems like 3.5 in your case).

[alexhelvetica]

Only one of the cores can get to 4.0GHz

It borrows performance from other cores.

It is made for single cored workloads 

[SkywardKkalox]

Turbo boost is only for 1 core, which happens on games mostly. Since video rendering is a multi threaded work load, turbo boost won't kick in.

[thedragon0000]

The 4.0GHz boost will kick in only when max 2 cores are working. When all 4 cores at at 100% there will be a lower boost (seems like 3.5 in your case).

If all 4 cores speed up to 4.0GHz, will it improve performance while gaming and reduce rendering time?

[alexhelvetica]

If all 4 cores speed up to 4.0GHz, will it improve performance while gaming and reduce rendering time?

yes but you would have to OC the cpu

[SkywardKkalox]

If all 4 cores speed up to 4.0GHz, will it improve performance while gaming and reduce rendering time?

Gaming? Maybe.

Rendering? Maybe - most likely.

 

CPU overclocking doesn't give much boost on games.

[GM_Peka]

Alot of motherboards have an option that allows turbo frequency (4.0GHz) on all cores, I wouldn't even call it overclocking, do you know what motherboard your friend has?

[NumLock21]

4ghz is for 1 core, the more core it has enabled, the lower the turbo boost across all cores.