Question How to get single CPU core to hit max clocks?

[bobertomarley]

Hi all,

I have an old ideapad with an AMD A6 4455m "dual core" CPU I'm readying to sell. Before I wiped the drive and did a clean reinstall, the CPU would regularly hit 2.9ghz single core boost (per Windows Task Manager) in random use when a bunch of apps were running. I was surprised to find the specs online state the max boost clock is 2.6 ghz; so maybe my unit hit the "silicon lottery."

My question is, what's a generally effective way to get a single core to hit max boost clocks? I tried running a single thread test on Prime95; oddly enough when I run the test, CPU usage goes to 100, however the clock remains at its base clock of 2.1GHz, so this is puzzling. (Maybe for thermal throttling? But the weird part is it didn't even spike past base clock for a split second, it just went from 1.6ghz idle at single digit % usage to 2.1ghz 100% usage per TaskManager)

Aside from reinstalling tons of misc. apps to repeat how I got it to 2.9ghz in the past, what's a generally good way to get a CPU to hit its max single core boost clock speed? I want to get it up there again so I can screen shot it.

Are there any apps that are generally known to reliably cause a CPU to hit its max clock speeds?

Thanks in advance!

 

[Dunlop0078]

Make sure the power plan is set to balanced in windows power settings, this should get you to the 2.6ghz boost clock under load if temps allow. That CPU should never have been hitting 2.9ghz unless it was overclocked, are you absolutely sure you saw it hitting 2.9ghz? No it has nothing to do with the silicon lottery, that simply means some CPU's even of the same model can overclock higher than others, it would not change a CPU's set turbo speed.

You should not overclock a laptop CPU like that even if it will allow you to and I doubt it will, certainly not multiplier overclocking, maybe BLCK. If I saw someone advertising an old overclocked laptop for sale I would avoid it personally, certainly wouldn't be a selling point.

 

[bobertomarley]

Make sure the power plan is set to balanced in windows power settings, this should get you to the 2.6ghz boost clock under load if temps allow. That CPU should never have been hitting 2.9ghz unless it was overclocked, are you absolutely sure you saw it hitting 2.9ghz? No it has nothing to do with the silicon lottery, that simply means some CPU's even of the same model can overclock higher than others, it would not change a CPU's set turbo speed.

You should not overclock a laptop CPU like that even if it will allow you to and I doubt it will, certainly not multiplier overclocking, maybe BLCK. If I saw someone advertising an old overclocked laptop for sale I would avoid it personally, certainly wouldn't be a selling point.

Yeah it hit 2.9ghz straight out of the box 100%; I'm the original owner, never OC'd it, that's why I was surprised. It never had overheating issues either. I'm one of those people that likes to have task manager open most of the time, it was a regular occurance to see it spike to 2.9ghz all stock settings.

I just checked- by default Windows already set it to balanced. When I test the browser it will have spikes up to 2.5ghz, but Prime95 for some odd reason never lets it go past 2.1ghz, not even for a second.

EDIT: I tried running CPU-Z bench as well; weirdly just like Prime95, it sits at 2.1ghz and won't activate boost clock. Browsing and windows background processes however do activate the boost clock.

Is this normal- do Prime95/CPU Z bench normally NOT activate boost clocks?

 

[Dunlop0078]

No that is not normal for any CPU I have ever tested, unless it is overheating or hitting some kind of power limit.

 

[Karadjgne]

Make sure you update the motherboard drivers, all of them. Resetting windows wipes them out.

To test for max speed, single core, use Prime95, but use small fft and set for only 1 worker. Using balanced or large adds a bunch of ram, so is less intensive on the cpu itself.