CPU not boosting and getting low frequency, why???

[gorrett]

So I am currently using a intelcore-I5-8250U it has a base frequency of 1.60Ghz and turbo up to 3.4Ghz my problem is that when i do any sort of 3d render the cpu only utilizes 83% specifically 83%and doesn't pass that. And the frequency it shows is 1.49Ghz i'm wondering what the problem is and from trouble shooting i can't find what could be causing this problem please help 

but once the system is idle the frequency jumps back to being normal and boosts to 3.4Ghz but only when the cpu is not under load

I also have power settings set to windows ultimate performance setting as shown below

 

[mbntr]

It's thermal throttling mate.

I don't know if it's normal in your laptop, but you should check the CPU temps, download something like core temp and you should see if it goes over the max temp (it should be around 100c)

 

Also MAX POWAH!!!

[WereCat]

You are probably hitting the power limit

[BlueChinchillaEatingDorito]

10 minutes ago, gorrett said:

So I am currently using a intelcore-I5-8250U it has a base frequency of 1.60Ghz and turbo up to 3.4Ghz my problem is that when i do any sort of 3d render the cpu only utilizes 83% specifically 83%and doesn't pass that. And the frequency it shows is 1.49Ghz i'm wondering what the problem is and from trouble shooting i can't find what could be causing this problem please help 

but once the system is idle the frequency jumps back to being normal and boosts to 3.4Ghz but only when the cpu is not under load

 

I also have power settings set to windows ultimate performance setting as shown below

 

 

Install Intel Power gadget and monitor your temps. I have a 8250U myself and it can get pretty toasty under load. 

[gorrett]

Thanks, ill try that right now

 

[Moonzy]

it's either thermal or power limit (i suspect power limit since the usage is pretty flat)

 

task manager monitors cpu usage based on base frequency, so your base is 1.8, while your cpu is limited to run at 1.5, that's why you see "83%" usage, when it's actually fully loaded

 

1.5 / 1.8 = 0.83

 

for thermal limit, you'll see CPU clock speed fluctuate, but yours (based on cpu usage) is pretty flat

so it's probably a power limit

[gorrett]

3 minutes ago, Moonzy said:

it's either thermal or power limit (i suspect power limit since the usage is pretty flat)

 

task manager monitors cpu usage based on base frequency, so your base is 1.8, while your cpu is limited to run at 1.5, that's why you see "83%" usage, when it's actually fully loaded

 

1.5 / 1.8 = 0.83

 

for thermal limit, you'll see CPU clock speed fluctuate, but yours (based on cpu usage) is pretty flat

so it's probably a power limit

Yeah i look at  the core temps and across all cores its around 60c. but if its power limit how to i resolve it. I should probably mention by now that i did use intel XTU but i only increase the amount of power it could use but later deleted the app since i suspected that of possibly being the one responsible

 

[Moonzy]

1 minute ago, gorrett said:

but if its power limit how to i resolve it.

you cant if it's limited by your laptop's manufacturer

 

edit: and shouldnt

[VeganJoy]

7 minutes ago, Moonzy said:

you cant if it's limited by your laptop's manufacturer

 

edit: and shouldnt

wew that sucks, though it makes sense. seems like op has plenty of thermal headroom to work with, theres no way to unlock the usual boost clocks as a "permanently" allowed boost frequency? i forget the terminology

[Moonzy]

4 minutes ago, VeganJoy said:

theres no way to unlock the usual boost clocks as a "permanently" allowed boost frequency?

depends on manufacturer, but they set the limit for a reason and removing it could potentially overload the VRM

CPU temp is only part of the story.

[-rascal-]

6 minutes ago, VeganJoy said:

wew that sucks, though it makes sense. seems like op has plenty of thermal headroom to work with, theres no way to unlock the usual boost clocks as a "permanently" allowed boost frequency? i forget the terminology

 

1 minute ago, Moonzy said:

depends on manufacturer, but they set the limit for a reason and removing it could potentially overload the VRM

CPU temp is only part of the story.

 

Ditto.

i5-8250U, at "stock" is rated at 15W TDP, BUT can be configured DOWN to 10W, or UP to 25W.

 

The i5-8250U (and similar CPUs) is usually put into low-powered and thinner notebooks / laptops, where battery up-time is priority.

Example, my Lenovo ThinkPad T480 has a i5-8250U in there, and they advertise "up to" 14.5 hours of battery life (and ~30 hours with the larger battery pack).

[gorrett]

6 minutes ago, Moonzy said:

depends on manufacturer, but they set the limit for a reason and removing it could potentially overload the VRM

CPU temp is only part of the story.

thanks a lot, it does suck if i cant change it. but the thing is it sometimes would boost to 3.4ghz and that is while its at 100% so i don't know what has changed since to cause this

[VeganJoy]

9 minutes ago, Moonzy said:

depends on manufacturer, but they set the limit for a reason and removing it could potentially overload the VRM

CPU temp is only part of the story.

if that would overheat the vrms wouldnt running at the normal boost clock for any decent amount of time overheat it as well? if so thats some impressive corner-cutting but makes sense to limit it

[gorrett]

3 minutes ago, -rascal- said:

 

 

Ditto.

i5-8250U, at "stock" is rated at 15W TDP, BUT can be configured DOWN to 10W, or UP to 25W.

 

The i5-8250U (and similar CPUs) is usually put into low-powered and thinner notebooks / laptops, where battery up-time is priority.

Example, my Lenovo ThinkPad T480 has a i5-8250U in there, and they advertise "up to" 14.5 hours of battery life (and ~30 hours with the larger battery pack).

the TDP is only 7W though whenever its rendering, the full spec of my system is a lenovo ideapad 330s-15Ikbm with 4 and 8gb ram (12gb) 2400Mhz ddr4, intel uhd graphics 620 and the stated cpu

 

[Moonzy]

4 minutes ago, gorrett said:

but the thing is it sometimes would boost to 3.4ghz and that is while its at 100% so i don't know what has changed since to cause this

different instruction requires different amount of power to run, so your CPU can boost higher for some tasks

 

2 minutes ago, VeganJoy said:

if that would overheat the vrms wouldnt running at the normal boost clock for any decent amount of time overheat it as well? if so thats some impressive corner-cutting but makes sense to limit it

refer to above

plus, single core boost isnt gonna draw as much power as all core under load

when your task manager says '5.0GHz', that's the highest clock speed core, not all core

you need cpu-z to monitor individual core freq

[VeganJoy]

1 minute ago, Moonzy said:

different instruction requires different amount of power to run, so your CPU can boost higher for some tasks

 

refer to above

plus, single core boost isnt gonna draw as much power as all core under load

when your task manager says '5.0GHz', that's the highest clock speed core, not all core

you need cpu-z to monitor individual core freq

yeah ik, but it seems like op's isnt boosting during heavy workloads at all. in XTU cant you set the tdp to a higher limit to allow for longer sustained boost clocks? even if you only end up with like 2ghz all core in renders thatd be at least a little improvement

[gorrett]

6 minutes ago, Moonzy said:

different instruction requires different amount of power to run, so your CPU can boost higher for some tasks

 

refer to above

plus, single core boost isnt gonna draw as much power as all core under load

when your task manager says '5.0GHz', that's the highest clock speed core, not all core

you need cpu-z to monitor individual core freq

Alright so i just did a stress test using intel xtu and across all cores I'm getting 100% as well as the clock speed was around the 3ghz mark its dropped to 2 ghz now but this is confusing because blender renders only uses 83% at 1.5ghz

 

[Moonzy]

5 minutes ago, VeganJoy said:

XTU cant you set the tdp to a higher limit to allow for longer sustained boost clocks?

not familiar with XTU to comment, but probably not if it's locked in firmware

 

6 minutes ago, VeganJoy said:

but it seems like op's isnt boosting during heavy workloads at all.

because of... power limit...

 

4 minutes ago, gorrett said:

Alright so i just did a stress test using intel xtu and across all cores I'm getting 100% as well as the clock speed was around the 3ghz mark its dropped to 2 ghz now but this is confusing because blender renders only uses 83% at 1.5ghz

 

14 minutes ago, Moonzy said:

different instruction requires different amount of power to run, so your CPU can boost higher for some tasks

 

[gorrett]

3 minutes ago, VeganJoy said:

yeah ik, but it seems like op's isnt boosting during heavy workloads at all. in XTU cant you set the tdp to a higher limit to allow for longer sustained boost clocks? even if you only end up with like 2ghz all core in renders thatd be at least a little improvement

I

 

2 minutes ago, Moonzy said:

not familiar with XTU to comment, but probably not if it's locked in firmware

 

because of... power limit...

 

 

 

soi just realised something...and it makes me feel kinda dumb, moonzy you were right about it being power limit. with the position i have my laptop charger plugged in i am not able to see it. it turns out it was just plugged out, i was starting to get really worried and wondered if somthing was wrong with my cpu since i only recently upgraded nothing should have been happening. Thanks alot guys i probably wouldn't have found out that it was plugged out until it died, i tested it while it was pluggedin and the frequency did go up to 3.34ghz and then i plugged it out and it dropped to the exact 83% 1.5ghz i'm really sorry for wasting your time on a mistake as dumb as this

 

[Moonzy]

2 minutes ago, gorrett said:

it turns out it was just plugged out

ah, didnt think about catching that

been too long since i dealt with mobile stuff

 

but yea, your laptop limits power when it's on battery to preserve the battery's lifespan

 

3 minutes ago, gorrett said:

i'm really sorry for wasting your time on a mistake as dumb as this

all good, no need to apologise

[gorrett]

3 minutes ago, Moonzy said:

ah, didnt think about catching that

been too long since i dealt with mobile stuff

 

but yea, your laptop limits power when it's on battery to preserve the battery's lifespan

 

all good, no need to apologise

thanks a lot again for the help

[VeganJoy]

haha thats great, glad it works fine. have a good day!