Understanding Turbo Boost

nheather

nheather

nheather

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I have a PC with an older CPU. i’m not about to change the CPU, Motherboard, RAM so I’m going to try some overclocking.

My CPU has a core clock speed of 3.5GHz and a boost clock speed of 3.9GHz.

I assume this means that when the CPU load reaches some threshold, like when playing a game, the CPU will boost upto 3.9GHz.

So that would suggest for overclocking purposes I should be looking at a minimum of 3.9GHz otherwise there is no point - is that correct?

I also assume that if I do set the core clock speed to 4.0GHz that I should disable the Turbo Boost because it is unnecessary.

Is my thinking correct?

Cheers,

Nigel
 
Pretty accurate so far - the clock speed is raised based on demand and providing temperatures and other limits are ok, stock clock speed can be exceeded on some/all cores.

It would help to know what generation CPU you have and how many cores. With modern turbo boost (maybe even all i7s, certainly since 2nd/3rd generation), they can boost one core higher than they will allow 2/3/4 cores to boost.

Yes, overclocking negates the need for the turbo boost. But you can still let the clock speed throttle down when not under load - this can be done in Windows settings.

Regarding the specific clock speed - while 3.9GHz is the max turbo clock, that's probably single core only. So setting all cores to 3.9GHz would still give a performance boost, assuming you use more than one core. Games have only recently starting using multiple cores seriously, but it will become more relevant. Other tasks like video encoding and similar can require more cores.
 
It’s an old 4th gen i5, a 4690K, but I don’t really have any issue with it, certainly not enough to splash out on a new mobo, cpu, cooler and RAM, so just trying to tease a little more out of it.

Cheers,

Nigel
 
nheather said:
It’s an old 4th gen i5, a 4690K, but I don’t really have any issue with it, certainly not enough to splash out on a new mobo, cpu, cooler and RAM, so just trying to tease a little more out of it.

Cheers,

Nigel
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Those can clock pretty high if you get a good one. I have a pretty poor chip and I found an all-core overclock of 4.2GHz was easy to achieve. I stopped there as it's not holding anything back, but plenty of others have happily run 4.5-4.6 for years.

I wouldn't overclock using a stock cooler, what are you using? A £20-30 cooler should be enough for a mild overclock though.
 
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